Tactful	animals:	How	the	study	of	touch	can	inform	the	animal morality	debate Susana	Monsó	&	Birte	Wrage1 PENULTIMATE	VERSION:	Accepted	for	publication	in	Philosophical	Psychology Abstract: In	this	paper,	we	argue that	scientists	working	on the	animal	morality	debate have	been	operating	with	a	narrow	view	of	morality	that	prematurely	limits	the	variety	of moral	practices	that	animals	may	be	capable	of.	We	show	how	this	bias	can	be	partially corrected	by	paying	more	attention	to the touch	behaviours	of	animals.	We	argue that	a careful examination of the ways in which animals engage in and navigate touch interactions	can	shed	new	light	on	current	debates	on	animal	morality, like	the	study	of consolation	behaviour,	while	also	revealing further forms	that	animal	morality	may	take and	that	have	been	neglected	so far, like	capacities	of tolerance	or trust.	This	defence is structured	as	an	analysis	of	the	three	main	functions	of	touch:	the	discriminative	function, the	affiliative	function,	and	the	vigilance	function. Keywords: nonhuman animals; animal morality; moral emotions; touch; affiliation; vulnerability Funding information: This research	was funded by the FWF (project numbers P31466G32	and	M2518-G32). Acknowledgements:	This	research	was	presented	at	a	JACSON	meeting	at	the	University	of Vienna. The authors would like to thank the attendants for their feedback. Additional thanks	go	to	Kristin	Andrews,	Judith	Benz-Schwarzburg,	Antonio	Osuna-Mascaró,	and	two anonymous	reviewers	for	their	helpful	comments	on	previous	drafts	of	this	paper. 1	Unit	of	Ethics	and	Human-Animal	Studies,	Messerli	Research Institute,	University	of	Veterinary Medicine	Vienna.	susanamonso@gmail.com;	birtewrg@gmail.com Both	authors	contributed	equally	to	this	paper. 2 1.	Introduction Imagine the following scenario. You're at home	when suddenly your housemate enters, crying.	Not	knowing	what	the	matter	is,	you	immediately	walk	up	to	her	and	put	your	arm around	her,	trying	your	best	to	console	her.	As	you	take	a	glance	through	the	open	door you	realise	what	happened:	her	car	is	in	the	driveway	and	your	cat	lies	motionless	on	the ground	beneath it.	You freeze	and	then	push	your	housemate	away.	Trying	to	apologise, she	grabs	your	hands,	but	you	shake	her	off,	rush	outside,	kneel	down	beside	the	car,	and carefully	place	a	hand	on	your	cat's	body.	To	your	dismay,	he	doesn't	respond.	After	sitting with	him	for	a	while,	you	gently	pick	up	his	limp	body	and	cradle	him	in	your	arms. This little tale illustrates the extent to	which touch is naturally involved in our social	interactions.	In	fact,	humans	can	communicate	a	range	of	distinct	emotions	through touch alone (Hertenstein et al. 2009). Moreover, in human infancy, touch is a more important	and	earlier	mode	of	social	interaction	than	verbal	communication	(Hertenstein et	al.	2006),	and	communicative	touch	has	been	postulated	as	the	evolutionary	precursor to	language	(Ibid.).	Not	for	nothing,	touch	is	called	'the	first	sense': it is	the	first	sensory faculty to develop in the womb, and its neural receptor types are among the oldest in evolutionary	history	(Fulkerson	2014,	xii).	All	of	this	makes	it	likely	that	touch	also	plays an important role in the social lives of non-linguistic animals. But, importantly, the interactions	in	the	story	we	told	are	not	only	social,	they	have	a	moral	hue,	and	indeed	the characters use touch to express various moral emotions, such as sympathy, guilt, resentment, love, and	grief. This gives rise to the	question	we	want to address, namely, could	the	ways	in	which	animals	engage	in	and	navigate	touch	interactions	give	us	insight into	their	moral	capacities? In this	paper,	we	will	outline	how	the	animal	morality	debate	can	benefit from	a closer look at the role of touch in the social interactions of animals. This has been prompted	by	the	work	of	Maria	Botero	on	primate2	social	cognition,	in	which	she	suggests that	scientists	studying	joint	attention	and	theory	of	mind	need	to	move	away	from	a	focus on vision, because touch as 'the first sense' might be an earlier facilitator of these capacities	(Botero	2016,	2018a,	2018b).	We	think	that	the	importance	of	these	claims	on the role	of touch	extends	beyond	the specific case	of social cognition	and the	particular 2	Botero's	argument	applies	to	both	human	and	nonhuman	primates,	but in	referring	to	her	work we	shall	focus	on	the	case	of	nonhuman	primates.	Accordingly,	we	use	the	terms	'primate'	and	'ape' to	refer	to	nonhuman	ones. 3 order of primates. Although the animal morality debate is not characterised by a bias towards	vision,	we	will	show	that	scientists	have	been	operating	with	a	different	bias:	a narrow view of morality that prematurely limits the variety of moral practices that animals	could	be	capable	of.	This	bias	can	be	partially	corrected	by	paying	more	attention to	touch.	Our	aim	is	to	argue	that	a	careful	examination	of	touch	in	animals	can	shed	new light	on	current	debates	on	animal	morality,	like	the	study	of	consolation	behaviour,	while also	revealing	further	forms	that	animal	morality	could	take	and	that	have	been	neglected so	far,	like	the	capacities	for	tolerance	or	trust. We	will	begin	this	paper	by	giving	a	quick	overview	of	the	animal	morality	debate3 and	showing	how	the issue	of touch	has	received	only	scarce	and implicit	attention.	We will then defend	why this needs to be remedied. This defence	will be structured as an analysis	of	the	three	main	functions	of	touch	and	their	relevance	for	animal	morality.	The first two functions	(the	discriminative and the affiliative function)	are acknowledged	by Botero	and,	as	we	will	argue,	the	reasons	why	they	are	important	for	animal	morality	are closely	connected	to	the	reasons	why	Botero	considers	them	to	be	important	for	primate social	cognition.	The	third	function	we	will	consider	is	the	vigilance	function	as	described by	Filip	Mattens (2017),	which is	not	mentioned	by	Botero.	While touch in its vigilance role	may	not	be	so	relevant	for	social	cognition,	we	will	argue	that	this	is	a	crucial	function to	consider	when	discussing	the	role	of	touch	in	animal	morality. Before	we	begin,	we	must	make	a	short	terminological	clarification,	since	the	term 'touch' is	somewhat	ambiguous. If	we	exclude	all	metaphorical	and literary	uses,	we	can distinguish	two	broad	meanings.	On	the	one	hand,	'touch'	can	be	used	to	refer	to	(1)	two physical entities coming into contact,	which can	be either (a) the result of a	purposeful action	(e.g.	"I	touched	her	cheek")	or	(b)	a	non-voluntary	event	(e.g.	"The	two	umbrellas were touching").	On the	other	hand, 'touch'	can	also	refer (2) to the	act	of	perceiving	by means	of	the	tactile	sense	(e.g.	"She	touched	something	slimy"),	or	to	the	tactile	sense	itself (e.g.	"She	can	read	by	touch").	In	this	paper,	we	are	mostly	concerned	with	meaning	(1a). However, since acts of purposefully coming into contact	with a	physical entity typically entail perception by	means of the tactile sense, meaning (2) cannot be completely left aside.	The	only	sense	of	the	word	'touch'	we	are	not	concerned	with	is	(1b),	that	is,	nonvoluntary	touch.	This is	because	we	are	concerned	with	touch interactions	that	are, to	a certain degree at least, under the animals' control, for they are the ones that can be indicative	of	their	cognitive	and	emotional	capacities.	In	addition	to	excluding	all	forms	of 3	Throughout	the	paper,	we	will	refer	to	many	empirical	studies	to	substantiate	our	claims.	A	lot	of this	research	can	be	seen	as	ethically	problematic,	and	we	would	like	to	note	that	our	reference	to any	particular	study	does	not	imply	an	endorsement	of	its	methodology. 4 touch that occur non-voluntarily, we will also leave aside forms of touch that occur through a medium. This is purely for simplicity reasons, since we do not in principle exclude that there	may	be	moral capacities expressed through	distal touch (e.g. using a stick	to	probe	or	feel)	or	hybrid	forms	thereof	(e.g.	tacto-acoustic	signals	in	dolphins). 2.	The	neglect	of	touch	in	the	animal	morality	debate As	Fitzpatrick	(2017)	rightly	points	out,	there	are	two	distinct	discussions	contained	in	the animal	morality debate. One discussion, exemplified by the theoretical	work of authors such	as	Bekoff	and	Pierce	(2009)	and	de	Waal	(e.g.	1996),	but	especially	by	the	empirical studies done in labs and in the field, concerns the distribution in nature of certain psychological capacities that are generally understood to be indicators of (proto- )morality; capacities such as empathy, altruism, or inequity aversion. The other discussion,	present	in	the	work	of	philosophers	such	as	Korsgaard	(2006)	and	Rowlands (e.g.	2012),	centres	on	whether these	psychological	capacities	actually	deserve the label 'moral.' The first debate is	more of an empirical endeavour, the second one consists of conceptual	analysis	and	clarification.	In	this	paper,	we	are	mostly	concerned	with	the	first of	these	debates,	that	is,	with	addressing	the	empirical	study	of	the	distribution	in	nature of	moral	capacities.	Although	we	will	offer	some	conceptual	reasons for linking touch to morality, our	main aim is to highlight how	a close analysis of the touch interactions of animals	could	provide	evidence	of	psychological	capacities	that	are	directly	or	indirectly involved	in	moral	practices.	Those	readers	who	remain	uneasy	about	the	use	of	the	term 'morality'	to	describe	animal	behaviour	can	reinterpret	our	arguments	as	a	discussion	of proto-morality	in	animals.4 If	we	understand	the	animal	morality	debate	in	the	first	way	described	above,	we can	distinguish	three	broad	research	foci:	the	altruism	cluster,	the	fairness	cluster,	and	the empathy cluster.5 The altruism cluster consists of studies that investigate animals' 4	Though	we	will	often	use the term 'animals'	as	a shorthand,	our	analysis throughout the	paper mostly	focuses	on	nonhuman	social	mammals.	This	is	due	to	space	constraints	and	to	the	present bias	in	the	relevant	behavioural	and	physiological literature.	It	should	not	be	taken	as	an	a	priori exclusion	of	the	possibility	of	moral	practices	in	non-mammalian	species. 5	This	is	an	artificial	classification	and	not	all	studies	will fall	neatly	into	one	category	or	another. For	instance,	some	of	the	evidence	of	animal	empathy	comes	from	anecdotal	accounts	of	altruistic helping	(e.g.	Bates	et	al.	2008),	and	the	animals	in	the	altruism	experiments	may	be	motivated	to help	others	by	empathic	mechanisms.	In	addition,	it	should	be	noted	that	in	classifying	the	studies this	way	we	take	inspiration	in	the	three	clusters	of	animal	moral	behaviours	that	Bekoff	and	Pierce (2009)	talk	about.	However,	our	distinction	does	not	map	on	exactly	to	theirs.	While	we	talk	of	the altruism	cluster,	the	fairness	cluster,	and	the	empathy	cluster,	they	talk	of	the	cooperation	cluster, the empathy cluster, and the justice cluster. The change is not fortuitous.	We are not trying to reproduce	Bekoff and	Pierce's ideas, but rather capture the	main research foci of contemporary 5 capacity	to	engage	in	altruistic	helping,	that	is,	helping	behaviour	that	involves	no	direct gain or even	a	direct loss for the helper,	where the relevant behaviour is	motivated by concern for the other and not the result of pure self-interest. In addition to many observational	reports	of	wild	animals	helping	each	other	(e.g.	Bates	et	al.	2008;	Park	et	al. 2012),	there	are	also	several	experimental	studies	in	this	cluster.	The	latter	can	be	divided into two rough groups. The first one corresponds to what could be called the 'active helping' experimental paradigm, where animals are given the option of helping an individual	who is distressed or otherwise in need.6 The second group of studies in the altruism cluster corresponds to what is known as the 'prosocial choice' experimental paradigm,	where	animals	can	choose	to	spontaneously	benefit	another	individual	who	is not	necessarily	in	need	nor	actively	asking	for	help.7 The	fairness	cluster	consists	of	studies	that	investigate	whether	animals	possess	a sense	of	fairness.	In	the	field	of	comparative	psychology,	this	is	exemplified	by	the	inequity aversion	studies,	where	pairs	of	animals	are	rewarded	unequally	for	performing	the	same task	and their reactions	observed to see if they track this inequality.8	Animals' sense	of fairness has also been a research focus of observational studies, predominantly those concerned	with social play. Social play in	mammals	often involves	behavioural	patterns that	are	similar	to those	used	in	predation	or	mating.	To	avoid	misinterpretation	during play, these animals often	use	play	markers.	Different	species	of canids, for instance, use the	play	bow	as	a	signal	(Bekoff	1977)	and	chimpanzees	have	been	found	to	increase	their play	signaling	when	the	mother	of	their	play	partner	is	in	close	proximity,	presumably	as	a way	of	preventing	her from intervening	and	ending the	play	bout (Flack	et	al.	2004). In empirical approaches to animal	morality. Bekoff and	Pierce have a very broad	understanding of animal	morality, and their three clusters encompass a	wide range of behaviours, since they use them to illustrate the different forms that animal morality could take. Under cooperation they include "altruism, reciprocity, honesty,	and trust;" under empathy, "sympathy, compassion, grief, and consolation;" under justice, "sharing, equity, fair play, and forgiveness" (Bekoff and Pierce 2009,	xiv).	While	we	think	that	their	open-mindedness	is	commendable,	it	is	an	exception	and	not the	rule	in	the	animal	morality	debate.	This	broad	understanding	of	morality	does	not	correspond to	how	animal	morality	is	being	systematically	studied.	There	are,	for	instance,	barely	any	studies on honesty, trust, or forgiveness in animals. We are therefore using these three clusters in a narrower	sense,	as	explained	below. 6	Positive	results	in	the	'active	helping'	sub-group	have	been	obtained	with	rodents	(e.g.	Bartal	et	al. 2011;	Ueno	et	al.	2019),	pigeons (Watanabe	and	Ono	1986),	and	primates (e.g.	Masserman	et	al. 1964;	Warneken	and	Tomasello	2006). 7	Positive	results	using	this	paradigm	have	been	obtained	with	chimpanzees	(Horner	et	al.	2011), capuchin monkeys (Lakshminarayanan and Santos 2008), common marmosets (Burkart et al. 2007), cotton-top tamarins (Cronin et	al. 2010), rats (e.g.	Hernandez-Lallement et	al. 2015) and parrots	(Brucks	and	Bayern	forthcoming). 8	Apparent	'inequity	aversion'	has	been	found	in	chimpanzees	(e.g.	Brosnan	et	al.	2010),	capuchin monkeys (Brosnan and de	Waal 2003) cotton-top tamarins (Cronin and Snowdon 2008), longtailed	macaques	(Massen	et	al.	2012),	dogs	(e.g.	Range	et	al.	2009),	rats	(Oberliessen	et	al.	2016), crows,	and	ravens	(Wascher	and	Bugnyar	2013). 6 order to	play 'fairly',	mammals also engage in self-handicapping,	which	occurs	when	an animal does not use her full strength when playing with another individual, and rolereversing, which takes place when an animal engages in a behaviour that does not correspond	to	her	relative	place	in	the	hierarchy	(Špinka	et	al.	2001). The last big research focus corresponds to the empathy cluster. This comprises studies	on	emotional	contagion,	the	spontaneous	'catching'	of	another's	emotion,	which	is widely	viewed	as	a	basic	form	of	empathy.	This	ability	is	commonly	tested	in	animals	by providing	them	with	visual	or	auditory	access	to	emotional	cues	from	another	individual, and	measuring	whether	there	are	any	signs	of	emotional	state-matching	in	the	witnessing subject.9	The	empathy	cluster	is	also	made	up	of	experimental	and	observational	studies that have documented consolation behaviour, which is a form of affiliative behaviour directed	at individuals in	distress	and is thought to	be triggered	by	empathic	processes. Apparent	consolation	has	been	observed	in	a	wide	range	of	animals,	including	some	avian species	(see	Table	1). As	one can see from this	quick overview, the topic of touch has received scarce attention in these debates. In the tests that are commonly used to study these moral capacities	in	animals,	the	experimental	subjects,	when	there	is	more	than	one,	are	usually separated	from	each	other,	in	order	to	facilitate	testing	and	avoid	any	confounding	factors. Thus, the test	conditions tend	to	physically	prevent	animals from	touching	one	another. Obviously, this is not the case in field studies, where the natural interactions of wild animals are observed. Although animals often touch each other when they engage in helping	and	play	behaviours,	this	specific	issue	has	not	been	the	explicit	focus	of	studies	to date.	An	exception	to	this	lack	of	attention	to	animal	touch	is	provided	by	the	consolation studies. Consolation behaviour in animals was first described by de Waal and van Roosmalen (1979). It is defined	as "an increase in	affiliative contact in response to and directed	toward	a	distressed	individual,	such	as	a	victim	of	aggression,	by	an	uninvolved bystander, which produces a calming effect" (Burkett et al. 2016, 375, our emphasis). Thus, the idea of touch ('affiliative contact') is present in the very definition of this behaviour. However, even though the majority of criteria used to identify consolation involve the animals touching in one way or another (see Table 1), scientists do not explicitly	reflect	on this, to the	extent that 'touch' is	often	listed	as	a	separate	behaviour 9	The	available	evidence	suggests	that	emotional	contagion	is	an	ability	possessed,	at	the	very	least, by chimpanzees (Parr 2001), greylag geese (Wascher et al. 2008), dogs (e.g.	Huber	et al. 2017), mice (e.g. Langford et al. 2006), rats (e.g. Atsak et al. 2011), prairie voles (Burkett et al. 2016), chickens (Edgar	et al. 2011), pigs (e.g.	Goumon and Špinka 2016), cockatiels (Liévin-Bazin	et al. 2018),	and	kea	(Schwing	et	al.	2017). 7 instead of as a common denominator. The general focus of the consolation studies has been on who is involved in the consolation interaction, what happened immediately before	the	consolation	event,	what	happened	afterward,	and	what	are	the	motives	of	the consoler.	Although consolation is largely thought to	occur via touch, the implications	of this	are	not	explicitly	reflected	upon. Study Species Other-directed	affiliative	behaviours	used	as	consolation	indicators de	Waal	and van Roosmalen 1979 Chimpanzees Kissing,	embracing,	hold-out-hand,	touching,	submissive	vocalisations Kutsukake	and Castles	2004 Chimpanzees Allo-grooming,	sitting	in	contact,	gentle	touching,	kissing,	embracing,	wrapping an	arm	around	another,	passing	touch,	mounting,	grasping	testicles,	playing, inspecting	another's	genitals Palagi	et	al. 2004 Bonobos Contact	sitting,	grooming,	touching	(gentle	patting	or	stroking	movements), sociosexual	behaviours,	play Cordoni	et	al. 2006 Gorillas Contact	sitting,	embracing,	grooming,	touching,	touching	in	walk,	playing Seed	et	al. 2007 Rooks Bill	twining Fraser	et	al. 2008 Chimpanzees Kissing,	embracing,	grooming,	finger-in-mouth	touching,	gentle	touching, playing,	submissive	pant-grunt	greeting Palagi	and Cordoni	2009 Wolves Body	contact,	social	licking,	social	play,	inspecting,	social	sniffing Cozzi	et	al. 2010 Horses Mutual	grooming,	friendly	contact,	nasal	sniff,	body	sniff,	genital	sniff,	play, approach,	follow Fraser	and Bugnyar	2010 Ravens Contact	sitting,	preening,	beak-to-beak	touching,	beak-to-body	touching McFarland	and Majolo	2012 Barbary macaques Grooming,	body	contact,	mutual	teeth	chattering,	successful	<1.5m	approaches Clay	and	de Waal	2013 Bonobos Embracing,	socio-sexual	contact	(genito-genital	contact,	mounting,	copulating, genital	touch),	touching,	grooming,	contact	sitting,	holding,	patting,	playing, inspecting Palagi	and Norscia	2013 Bonobos Grooming,	touching,	contact-sitting,	embracing,	kissing,	socio-sexual interactions,	social	play,	food-sharing Baan	et	al. 2014 Wolves Body	contact,	nose	touch,	licking,	playing,	greeting,	sniffing,	inspecting Palagi	et	al. 2014 Japanese macaques, Tonkean macaques Grooming,	contact	sitting,	touching,	playful	contacts,	mounting,	manipulating genitals,	copulating,	kissing,	mouthing,	cheek-to-cheek,	face	holding,	face sniffing Plotnik	and	de Waal	2014 Asian elephants Body	contact,	vocalisations Burkett	et	al. 2016 Prairie	voles Licking,	grooming QuervelChaumette	et al.	2016 Dogs Affiliative	behaviours:	rubbing	one's	own	body	alongside	that	of	the	partner, greeting	(licking	the	lips	of	the	partner,	whilst	tail	wagging),	play,	sniffing	any body	part;	time	spent	in	proximity This lack of attention to touch comes at an explanatory cost, since the neurophysiology of affiliative touch can shed some light on why consolation is Table 1. Consolation studies and the criteria used to identify consolation behaviour. In italics: those criteria	that	necessarily	entail	touch;	most	of	the	other	listed	behaviours	can	involve	touch	too. 8 comforting.10	It	has	recently	been	discovered	that	nerve	fibres	found	in	hairy	mammalian skin,	which	covers	major	parts	of	most	mammalian	bodies,	seem	to	be	specifically	attuned to	processing	social	touch,	especially	affiliative	touch	in	the	form	of	slow,	gentle	stroking (Löken et al. 2009; McGlone et al. 2014). These nerve fibres, called C-tactile afferents, apparently	process slow, gentle touch as 'pleasant' and 'affiliative' the	way other nerve fibres, for example, process	noxious stimuli	as 'painful' (Löken	et	al. 2009). Consolation behaviour in the form	of	slow,	gentle	touch is thus likely	especially	effective in	having	a calming effect. Of course, other factors like social context also influence how touch is ultimately experienced. However, CT afferents point to a significant 'social bias' of the mammalian	nervous	system.	The	importance	of	considering	these	socially-attuned	nerve fibres	is	further	underlined	by	the	fact	that	they	have	been	found	in	all	species	examined, i.e.	primates,	pigs,	rats,	mice,	guinea	pigs,	rabbits,	and	cats,	and	it	has	been	suggested	that all	mammals	possess them	(Morrison	2012;	Pitcher	et	al.	2016).	Despite its	explanatory potential,	the	neurophysiology	of	affiliative	touch	is	hardly	considered	in	the	consolation studies.11	We	propose	that	greater	attention	to	the	identification	of	consolation	behaviour with	a	certain	kind	of	touch	may	inform	research	in	this	area. This	overview	of the	animal	morality	debate	not	only	shows	that	scientists	have paid only scarce and implicit attention to the issue of touch, but also that they have operationalised	morality in a rather narrow	way. There are	many other ways of being moral12 besides being empathic, altruistic, and averse to inequity. These include being grateful, caring, trusting, tolerant, and loyal, as	well as	being resentful, envious, jealous, disgusted, and cruel. This narrow conception of morality is not the sole fault of the scientists, but is surely influenced by moral philosophers, who have traditionally attempted to reduce morality to one or two key capacities. And naturally there are exceptions on both sides. Among the scientists, Bekoff (Bekoff and Pierce 2009) has defended a pluralistic account of morality. Among the philosophers, Pierce (Ibid.), Rowlands (2012), Monsó and Andrews (forthcoming), and Rutledge-Prior (2019) have also given accounts of animal morality that presuppose a pluralistic framework. We propose that this pluralistic approach is the way to go, since opting for a narrow operationalisation of	morality could amount to a	premature reduction that failed to do 10 Scientists clearly expect consolation to be comforting, because they often either define consolation as a behaviour that produces a calming effect or they look for evidence of a stress reduction	in	the	consoled	individual.	However,	to	the	best	of	our	knowledge,	none	of	the	scientists working	on	consolation	have	explained	why	they	expect	the	behaviours	that	they	deem	indicative	of consolation	to	be	comforting. 11	A	single	study	on	prairie	voles	(Burkett	et	al.	2016)	mentions	the	role	of	oxytocin,	a	mammalian hormone	associated	with	social	touch	(Uvnäs-Moberg	et	al.	2005)	and	attachment	(Feldman	2011, 380),	in	consolation	behaviour. 12	We	are	using	the	term	'moral'	not	in	its	normative	but	in	its	descriptive	sense. 9 justice to the range of moral practices that animals are potentially capable of. Though some of these practices may be out of reach for animals, this should not be assumed without	empirical	investigation. We will argue that animals' touch interactions could reveal nuances in the practices	thus	far	considered	in	the	animal	morality	debate	(such	as	consolation	and	social play), while at the same time providing evidence of some of these alternative ways of being	moral.	Our focus throughout the	paper	will be	on	potential cases	of	what	we call 'moral	practices,'	which	we	define	as those that involve the	exercise	of	moral	capacities. Since we do not want to circumscribe our claims to a particular account of moral capacities, the readers should understand this term in a broad sense, as capacities that imply a "sensitivity to [some of] the goodor bad-making features of situations" (Rowlands 2012, 230) or as those	whose exercise conveys information about a being's moral character (Parrott 2019). We understand moral capacities to include moral emotions	(those	that	are	involved	both	in	pro-social	and	in	anti-social	behaviour),	as	well as other capacities that can't be classified as emotions but could still be said to 'track' moral properties (in Rowlands' [2012] sense), such as trust, care, or normative capacities.13 For the	purposes	of this	paper, it is not	necessary that	we take a stand	on whether	any	of	these	capacities	on	its	own	is	enough	to	endow	an	animal	with	full-blown morality.	Instead,	what	we	will	argue	is	that	looking	at	animals'	touch	interactions	has	the potential	to	help	reveal	many	of	these	(proto-)moral	capacities.14	In	what	follows,	we	will explain	this	by	analysing	the	three	functions	of	touch	and	their	connection	to	potentially 13	We	understand	'normative	capacities'	as	the	ability	to	make	normative	evaluations	about	others' behaviour,	as	well	as	the	ability	to	comply	with	and	enforce	normative	standards	of	behaviour.	See section	5. 14	An	interesting	question	posed	by	a	reviewer	is	whether	there	are	studies	that	employ	the	frame of	touch	to	explore	morality	in	humans.	Studies	on	human	moral	psychology	mostly	focus	on	gaze (e.g. showing clips of antagonistic interactions and just or unjust punishment to pre-linguistic children and tracking their gaze to infer their understanding of norms and fairness), visualor auditory-mediated	emotional	contagion	(e.g.	babies	crying	in	response	to	hearing	another	baby	cry as	an	indicator	of	the	innateness	of	empathy),	and,	as	soon	as	developmentally	possible,	language (e.g.	to	inquire	about	moral	judgments).	Since	humans	have	linguistic	abilities,	studies	of	our	moral capacities	may	not	benefit	as	much	from	a	focus	on	touch	as	the	study	of	animal	morality.	However, some	studies	do	document	the	role	of	touch	in	humans'	moral	interactions	broadly	construed.	For instance,	affective	touch	has	been	found	to	affect	our	impression	of	others	(e.g.	Fisher	et	al.	1976), and	to	have	a	positive	effect	on	compliance	and	cooperation	in	mundane	situations	(e.g.	Goldman	et al.	2010),	which	may	affect	moral	decision-making,	e.g.	in	the	context	of	helping.	Affective	touch	is also	a	prominent	criterion	in	the	studies	of	consolation	in	pre-linguistic	infants	or	infants	in	early linguistic	development.	Consolation	in	these	infants	is	operationalised, like	in	animals,	as	hugging the distressed other or offering some other form of comfort contact (e.g. Zahn-Waxler 1992). Researchers have also found an analgesic effect of partner touch,	which increases	when a	more empathic	partner	provides	the	touch	(Goldstein	et	al.	2018;	Goldstein	et	al.	2016).	Lastly,	touch	may also play a role in the experiencing of moral disgust, though it should be noted that the link between	physical	revulsion	as	a	protective	mechanism	and	moral	disgust	is	controversial	(Oaten	et al.	2018). 10 moral	practices.	Though	we	will	separate	these	three	functions	for	analytic	purposes,	it	is important	to	bear	in	mind	that	in	reality	they	intertwine	and	support	each	other. 3.	The	discriminative	function	of	touch	and	its	importance	for	animal	morality Touch in its discriminative function serves	as a	perceptual source	of information.	When the	body	of	a	being	with	a	tactile	sense	comes	into	contact	with	a	physical	entity,	there	is some information made available to that being about the qualities of the entity being touched, such as its shape, temperature,	motion, texture,	malleability, and	so	on.	This is the	discriminative	function	of	touch,	and	it	does	not	reduce	to	the	touching	of	inanimate objects, but extends to touching other living beings. For this reason, Botero has argued that	discriminative touch	must be factored into	discussions on	primate social cognition (Botero	2016,	1203–4).	In	this	section,	we	will	show	how	this	should	be	extended	to	the animal	morality	debate. In	arguing	for	the	importance	of	discriminative	touch	in	primate	social	cognition, Botero	is	going	against	the	general	trend	in	debates	and	experiments	on	this	topic,	which, as she herself points out, have been characterised by an almost exclusive focus on the visual	sense.	Joint	attention,	for	example,	is	commonly	understood	as	a	triadic	interaction occurring	between two	subjects	who coordinate their attention	on	one	object.	Although attention is not necessarily linked to visual perception, most of the research on joint attention in	primates	has	been circumscribed to testing their ability to follow	another's gaze	on	an	object	(see	Carpenter	and	Call	2013	for	a	review).	Research	on	theory	of	mind in	primates	has	likewise	privileged	the	visual	mode.	Although	theory	of	mind	refers	to	the general ability to attribute mental states to others, a significant proportion of studies attempts to	determine	whether	primates	possess	a theory	of	mind	by	studying	whether they can	understand	what	others can	and cannot	see (see	Andrews	2017 for a review). And	even those studies that focus	on the attribution	of a	different type	of	mental	state, namely, emotions, tend to emphasise the sense	of	vision. Indeed,	a common	method for measuring emotions in primates concentrates on their facial expressions, which are a visual	way	of expressing emotions, and	most of the experiments that	have	been carried out	to	determine	whether	primates	can	attribute	emotions	to	others	have	tested	for	their ability	to	visually	discriminate	facial	expressions	of	emotions	(e.g.	Parr	2001;	2003). Botero suggests that the operationalisation of socio-cognitive capacities via the visual modality results in a limited understanding of social cognition in primates. She points	out,	for	instance,	that	chimpanzees'	facial	features	lack	the	salient	contrasts	that	in 11 our case allow for an easy visual	detection	of the subtle facial	movements that indicate emotions (Botero	2018b, 373).	This	means that the	discrimination	of facial expressions may	not	play	such	an	important	role	in	the	attribution	of	emotions	amongst	chimpanzees. In	addition,	chimpanzee	mothers	rarely	use	prolonged	gaze	as	a	form	of	interaction	with their	offspring.	However,	during	the	first	nine	months,	infant	chimpanzees	spend	most	of the	time	in	close	contact	with	their	mothers,	who	carry	them	around	as	they	go	about	their day.	By	means	of	this	touch	interaction,	the	infant	chimpanzee	learns	about	the	mother's reaction to	different stimuli, thereby	gaining information	on	her	perspective and	on the world	surrounding	them	(Botero	2016,	1204–5).	Botero	considers	that,	due	to	similarities in	neurophysiology	and	infant	development	across	primate	species,	these	points	probably generalise	to	other	apes.	Discriminative	touch	thus	likely	constitutes	the	very	first	source of	social	information	that	apes	make	use	of,	and	by	means	of	it	they	can	learn	"that	there are others and that these others have a different perspective, two basic traits of joint attention	and	theory	of	mind"	(Botero	2018b,	377). Since	discriminative touch is a source	of social information, and	moral	practices require	social	information,	discriminative	touch	can	support	moral	practices.	In	order	to respond in ways that are morally appropriate or that exemplify the use of a moral capacity, the animal first has to gauge the social situation.15 In certain circumstances, namely when there is bodily contact involved, the relevant social information can be gauged	by	means	of	touch.	For	instance,	in	the	case	of	consolation	behaviour,	the	consoler can	gain	tactile	information	on	whether	the	other	is	tense	or	relaxed,	which	can	be	used	to determine	when	the	contact	should	go	on	and	when	it	can	stop.	Likewise,	the	appropriate duration	of	other	affiliative	behaviours, like	grooming,	can	be	informed	by	touch,	e.g.	the groomer can	use it to	discriminate	when	the recipient is	annoyed	by	or	uninterested in this	interaction. Touch	can	also	be	used	to	gain	information	about	other	morally	relevant	features of	situations	besides	emotions.	An	example	of	this	is	provided	by	the	literature	on	animals' reactions	to	conspecifics'	deaths.	Death	can	be	construed	as	morally	relevant, insofar	as, other things	being equal, it is a bad-making feature	of situations that calls for a certain reaction in	beings	who care	about the	deceased. In	order to respond in	a	morally laden 15 This of course connects to theory of mind, and sometimes it may be useful (perhaps even necessary) for an animal to first determine that another is in a particular mental state before exercising	a	moral	capacity.	However,	we	do	not	want	to	circumscribe	our	claims	to	animals	who possess a theory of mind. Instead, we follow Andrews (2018) in considering that many sociocognitive	practices	don't	require	mindreading	but	trait	attribution,	understanding	of	past	history, relationship	status,	etc.,	and,	following	Monsó	(2015),	we	consider	it	quite	likely	that	this	pluralistic set	of	capacities	for	predicting	and	understanding	others	is	sufficient	for	the	exercise	of	many	moral capacities. 12 way	to	death,	animals	would	have	to	first	discriminate	that	they	are	dealing	with	a	dead individual, which could in principle be done through touch. In fact, a variety of social mammals	have	been	witnessed	insistently	touching	or	nudging	corpses	(for	reviews,	see Fashing	and	Nguyen	2011;	Boesch	2012,	chapter	7;	Anderson	2016).	The	meaning	of	this behaviour is unclear, but it entails bodily contact and thus offers the animals tactile information	that	points	to	the	state	of	the	dead	conspecific:	she	is	not	responding	the	way she usually would to touch, and she does not feel the way she used to, e.g. because of limpness or, later, rigor mortis and coldness. The death of a conspecific can thus be grasped	to	a	degree	by	means	of	the	tactile	sense.	Similarly,	touching	injured,	disabled,	or sick	conspecifics	may	provide	information	on	their	state	(e.g.	when	they	flinch	or	respond unusually	to	a	common	form	of	touch),	thus	providing	a	reason	to	adapt	one's	interactions with	them. Another	example	of	situations	in	which	social	information	can	be	gained	by	means of touch are play fights and aggressive encounters. Puppies are often described as not knowing their	own	strength	yet,	which	may	well	be	said for	any	mammalian	young	at	a certain developmental stage. Rough-and-tumble play provides an opportunity to learn about one's own and others' strength, information that is gathered most prominently through touch. Moreover, tactile information about the other's strength and character gained through	play and	aggressive interactions can shape relationships and	determine one's	own	and	the	other's	status,	which	could in turn	provide	a	context for	many	moral practices.	Deciding,	for	instance, if	and	when	to	share	food	with,	groom,	help,	or	console another	will	depend	on	the	characteristics	of	the	preexisting	relationship. These are just some examples of how touch can contain	morally relevant social information	regarding	others'	characteristics	and	present	state,	as	well	as	one's	capacities and relationship to others. Lack of attention to the discriminative powers of touch can result	in	scientists	misconstruing	or	simplifying	the	range	of	social	information	available to an animal in a certain situation. For instance, some scientists have speculated that monkey	mothers	who carry the	mummified remains of their dead infants for extended periods	of	time	perhaps	do	so	because	they	haven't	properly	processed	the	change	in	the infant's	state,	given	that	the	mummification	allows	the	corpse	to	retain	its	shape	and	still be visually recognisable as an infant (e.g. De Marco 2018). This ignores how radically different	a	dead	infant	will	feel	from	the	very	first	moment	when	compared	to	a	live	one. Incorporating the study	of touch as a	medium for social information can thus give	us a richer	and	more	accurate	account	of	the	mechanisms	underlying	the	behaviour	of	animals and	has	the	potential	to	help	us	uncover	moral	practices. 13 4.	The	affiliative	function	of	touch	and	its	importance	for	animal	morality Touching	another individual is	not	only	a	source	of information, it	can	also	be	a	form	of affiliation.	Although	the	term	'affiliation'	refers	to	any	behaviour	that	serves	to	strengthen social	bonds,	it	often	takes	the	form	of	voluntary	bodily	contact	between	individuals,	e.g.	in the	context	of	parental16	care	(Feldman	2011)	or	social	grooming	(Spruijt	et	al.	1992).	In this	section,	we	will	argue	that	affiliative	touch	is	linked	to	morality	(1)	indirectly,	due	to the	causal	connection	between	parental	touch	and	normal	development,	and	(2)	directly, since	affiliative	touch	could	be	an	expression	of	moral	emotions. The link between parental touch and development was demonstrated by the infamous maternal deprivation studies first conducted in the 1950s. In one of these studies	by	Harlow	(1958),	infant	monkeys	were	taken	from	their	mothers	and	were	either offered a surrogate	made of bare	mesh	wire or one draped in soft cloth.	When given a choice	between	the two	conditions, the	monkeys	strongly	preferred the	cloth	surrogate, even when only the wire surrogate provided food. While monkeys in both surrogate conditions took in the	same	amount	of	milk	and	gained	the	same	amount	of	weight, the monkeys in the	wire surrogate condition showed	psychosomatic symptoms,	which lead Harlow to conclude that "[t]he	wire	mother is biologically adequate	but	psychologically inept" (Harlow 1958, 677). Furthermore, in an open-field test, where Harlow put surrogate-raised	monkeys	in	a	room	with	novel	stimuli,	either	with	or	without the	cloth surrogate,	he	found	that	in	the	condition	with	the	surrogate	available	the	infants	displayed less behavioural signs of stress. The surrogate thus seemed to function as a "source of security"	(ibid.,	679). This research led to two novel insights relevant for our case that have been supported	by follow-up	studies: first,	parental	touch,	and	not	as	previously	assumed	the providing	of	food	by	the	parent,	seems	to	be	crucial	in	the	emergence	of	the	parent-infant attachment,	and	second,	touch	seems	to	decrease	negative	arousal.	This	apparent	soothing effect	is	immediate,	but	parental	touch	has	also	been	found	to	positively	influence	stress response in the long term, improving the adequacy of the individual's response to stressors and her ability to cope with stress throughout her life (for a review, see Hertenstein et al. 2006). Importantly, the significance of parental touch for the normal 16	We	use	the	terms	'parent'	and	'parental'	to	refer	to	any	primary	caregiver. 14 development	of	attachment	and	emotional	self-regulation	is	a	constant	across	mammalian species	(Hertenstein	et	al.	2006;	Feldman	201117). The	capacities	for	attachment	and	emotional	self-regulation	are	indirectly	relevant for	morality	because	they	enable	the	emergence	of	sociality.	We	understand	sociality	as	a prerequisite for	morality, since the ability to	abandon	a self-centred	stance is	necessary for	one's	attitudes to	be	directed towards the	welfare	of	others.18	And	as	Botero	argues, emotional self-regulation, facilitated by the soothing effect of parental touch, is a precondition	for	being	able	to	pay	attention	to	others	(Botero	2018b,	376–377),	which	is critical for behaviour to be other-directed. Furthermore, concern for others can be motivated	and	modulated	by	attachment,	for	which	the	parent-infant	attachment	seems	to act as a blueprint. This first attachment facilitates the emergence of capacities that are necessary	for	forming	further	social	bonds,	such	as	play	tendencies	(Lévy	et	al.	2003)	or social discrimination, the ability to distinguish familiar from unfamiliar conspecifics (Kentrop	et	al.	2018).	The	latter	has	also	been	found	to	play	a	crucial	role	in	the	triggering of	empathic	mechanisms	across	species	(de	Waal	and	Preston	2017).	Therefore,	parental touch	facilitates	basic	capacities	necessary	for	moral	practice. However,	parental	care	isn't	only	indirectly	relevant	for	animal	morality,	it	could also	be	a	direct	expression	of	moral	capacities.	To	the	extent	that	the	parent	is	motivated by	a	moral	emotion,	such	as	love,	whenever	she	grooms,	holds,	or	nurses	her infant,	we can	speak	of	her	affiliative	touch	as	a	moral	practice	in	itself.	Affiliative	touch,	however,	is not	exclusive	to	parent-infant	interactions,	but	is	instead	an	integral	part	of	the	social	lives of	many	animals at all developmental stages and	across	different sorts of relationships. Therefore, affiliative touch can also be an expression of moral emotions beyond the parent-infant bond. The most obvious example, which is widely studied and welldocumented in the literature, is consolation behaviour. This behaviour, as explained in 17 Feldman (2011, 373) notes: "Maternal touch patterns are among the most evolutionarily conserved	behaviors	and,	as	such,	there	is	marked	consistency	in	the	genetic,	neuroendocrine,	and brain	circuitry	between	humans	and	other	mammals.	[...]	Such	consistency	in	the	role	of	maternal touch	between	humans	and	other	mammals	renders	research	in	animal	models	particularly	useful for understanding the biological underpinnings of early touch and contact and their effect on shaping	the	infant's	capacity	for	social	affiliation	and	stress	modulation	throughout	life." 18	Although	in	this	section	we	emphasise	prosocial	behaviours,	given	that	the	focus	is	on	affiliation, the link between	morality	and sociality doesn't circumscribe solely the positive side of	morality. Cruelty, for	example, is	an	attitude that	has the	other's	(negative)	welfare	as its	goal	and, in that sense,	it	also	requires	abandoning	a	purely	self-centred	stance.	In	addition,	our	view	regarding	the importance	of	sociality	for	morality	should	not	be	taken	to	imply	that	egoism	or	callousness	are	not moral	attitudes.	Our	point	is	that	one	can	only	make	sense	of	the	morality	of	an	animal's	attitudes	if one assumes the animal has the capacity to abandon a self-centred stance. This applies also to callous and egoistic attitudes. Animals	who naturally lead solitary lives and lack all capacity to engage	with	others	could	not	be	said to	be	egoistic	or	callous,	at least	not in the	moral sense	of these	terms. 15 section	2,	occurs	as	a	response to	distress	behaviour in	others	and	most	often	takes	the form of affiliative touch. Consolation, in turn, is generally thought to be motivated by empathy	or	sympathy	(see	e.g.	de	Waal	and	Preston	2017), so	affiliative	touch	would	be functioning	here	as	an	expression	of	these	moral	emotions. Affiliative touch can also point us to other moral emotions beyond empathy, sympathy, and	parental love.	The	potential of affiliative touch to	uncover further	moral emotions	has to	do	with the strong	social	significance that this interaction	has in	many animal	societies.	Although	some	of	these	emotions	may	ultimately	be	beyond	the	reach	of (most)	animals,	we	propose	grief,	gratitude,	jealousy,	and	resentment	as	exemplary	moral capacities that could either be expressed by affiliative touch or through its prevention, disruption,	or	evasion.	Grief	may	be	manifested	by	means	of	affiliative	contact	towards	a corpse, including grooming, prolonged holding, and protective behaviours such as preventing others from touching it.19 Gratitude could be expressed by spontaneous affiliative touching directed at a benefactor. Jealousy, as a negative emotion evoked by affiliation in others, could take the form of attempts to prevent affiliative touch or to disrupt its occurrence. And lastly, resentment could be expressed in the aftermath of a conflict by avoiding the	offender's touch, ignoring	attempts	at	affiliation, or engaging in aggressive responses to affiliation attempts. The ways and contexts in which animals manifest	and	respond	to	affiliative	touch	could	thus	give	us	insight	into	moral	capacities that	have	received little	attention in the	animal	morality	debate	so far. In	addition, they also	point	to	the	importance	of	performing	field	studies,	since	these	capacities	could	never be detected without considering the social context and history in which they are embedded	and	without	allowing	for	animals	to	freely	and	spontaneously	engage	in	social interactions	with	their	conspecifics. 5.	The	vigilance	function	of	the	tactile	sense	and	its	importance	for	animal	morality Filip	Mattens	(2017)	has	argued	that	there	is	a	third	function	that	can	be	attributed	to	the tactile	sense, namely, the vigilance function.	Mattens criticises	philosophers	of touch for their excessive focus on the hands and the discriminative function of touch. Hands or organs	with the function of touching in order to feel are a rare feature once we	move beyond the primate order, and yet,	we attribute a tactile sense, at the very least, to all mammals. That is because the tactile sense is not something that is circumscribed to 19 The prolonged transportation and nurturing of an infant's corpse have been witnessed in mothers	from	a	wide	range	of	mammalian	species	(Reggente	et	al.	2016). 16 hands, but a body-wide feature. This, he argues, suggests that the basal function of the tactile	sense	is	not	its	discriminative	function: Although	not	all	areas	of	the	body	are	used	for	touching,	nearly	every	single	area can sense when something touches it. Because it signals when and where an animal is	being	touched,	tactile	sensitivity	functions	like	a	surveillance	system:	it keeps	a	watch	on	the	animal's	body.	(Ibid.,	690) The	vigilance	function	of	the	tactile	sense	is	distinct	from	its	discriminative	function.	This is	easily	illustrated	by	considering	cases	in	which	you	are	touched	by	something	that	is	not anticipated	by	your	other	senses	and	thus	met	with	a	startle	response:	"[a]s	soon	as	you sense the	slightest	contact,	you flinch	back.	You	do	not	wait	until it is	clear	whether the object is injurious; you flinch back before you even know what touched you" (Ibid., emphasis in the original). Touch in its vigilance function is not meant as a means for exploring	objects,	but	as	a	way	of	protecting the	body.	This function	of touch, therefore, "does	not first	and foremost	serve the	animal's	desire to touch,	but	rather	[her]	need to know	that	[she]	is	being	touched"	(Ibid.,	emphasis	in	the	original). The vigilance function of touch thus points us to the body's vulnerability. The tactile	sense	watches	over	the	body	because,	whenever	something	touches	our	body,	there is a potential threat to our health and integrity. And indeed, when an animal touches another,	she	is	invading	their	bodily	space,	thus	becoming	a	potential	threat	to	them	while also	risking	injury	herself.	Both	animals	are	made	more	vulnerable	by	this	interaction.	As we	will	argue	in	this	section,	studying	how	animals	navigate	this	increase	in	vulnerability that	occurs	as	a	result	of	touch	may	illuminate	further	moral	capacities.	In	particular,	it	has the	potential	to	reveal	capacities	of	trust,	care,	and	tolerance,	moral	capacities	involved	in antisocial	behaviour,	such	as	cruelty,	and	normative	capacities. Although	until	now it	has	barely	been taken	up	as	a	research	topic in	the	animal morality	debate,	trust	can	be	plausibly	regarded	as	a	moral	capacity	insofar	as	it	is	likely	a necessary	mechanism	(or	at	least	a	very	useful	one)	for	a	moral	society	to	function.	Moral societies	are	generally	regarded	as	ones	in	which	individuals	do	not	merely	pursue	their own	selfish	desires,	but	rather	decide	to	cooperate	and	look	out	for	others' interests	too (e.g.	Tomasello	2016).	In	order	to	ensure	that	this	works,	members	of	the	society	need	to place	trust	in	that	the	others	will	reciprocate	(Ibid.,	162ff.).	But	trust	may	also	be	involved in other interactions beside reciprocity. Whenever animals engage in behaviours like grooming,	contact	sleeping,	or	social	play,	they	are	placing	themselves	in	a	situation	that makes them more vulnerable, and insofar as it is under the animal's control to place herself	in	this	situation,	we	could	speak	of	a	capacity	of	trust	in	the	other,	which	would	be 17 more	or	less	explicit	depending,	perhaps,	on	how	aware	the	animal	is	that	the	other	could hurt	her. It could, however, be argued that common behaviours like grooming, contact sleeping,	or	social	play	do	not	necessarily	imply	that	the	animals	involved	trust	each	other; instead, perhaps they have	merely learnt which touch behaviours are safe or effective. This	may be true, but it does not necessarily exclude an explanation in terms of trust. Instead, this learning process	might precisely amount to a development of trust. Trust does not have to be something that is explicitly present in the animal's mind as a propositional	judgement	such	as	"This	individual	can	be	trusted."	Rather,	trust	may	be	a capacity that is implicit in their choosing to place themselves in a situation that	makes them	more	vulnerable. Another	objection	here	might	be	that	the	very	neurophysiology	of	touch,	which	we discussed in section 2, makes these sorts of affiliative interactions pleasurable for the animals,	so	that	there	is	no	role	for	trust	to	play,	but	rather	the	animals	are	just	motivated to	encourage	what	they	feel	as	a	pleasant	stimulus.	We	believe	that	it is	quite	likely	that part	of	the	motivation	for	engaging	in	affiliation	is	indeed	that	it	is	inherently	rewarding. However,	two	things	must	be	borne	in	mind.	The	first	one	is	that	the	individual	initiating the	affiliation	might	not	get	pleasure	out	of it right	away,	and	still this individual is	also risking injury. Second, and relatedly, the fact that the	neurophysiology	of touch ensures that	affiliation is	pleasant	does	not	mean	that things	can't	go	wrong.	Not	all	attempts	at affiliation	are	successful.	And	for	the	animal	on	the	receiving	end	there	is	always	the	risk of	misreading	the	situation,	interpreting	as	an	affiliative	approach	what	is	not,	which	likely means	that	the	animals	who	purposefully	let	others	touch	them	implicitly	trust	them. The	capacity	of	trust	may	also	be	manifested	in	certain	touch	behaviours	that	some animals engage in and that seem to create vulnerability as a gesture of reassurance or friendliness. One example first described in chimps has been aptly named 'vulnerable contact	behaviour'	and	consists	of inserting	a finger into	another's	mouth	(Nishida	et	al. 2010,	145),	either	to	appease	another	in	distress	or	to	reassure	oneself.	De	Waal	(1989) puts	the	use	and	risk	of	this	behaviour	into	context: Chimpanzees have a habit of putting their fingers or the back of one hand	between the teeth of dominant group	members.	A friendly gesture, it is also a test of the dominant's state	of	arousal	and	often is	used in	ambiguous	situations. I experienced it	myself	when performing	psychological	experiments	with	two	juvenile	chimpanzees	at	the	University	of Nijmegen. Each day I spent hours in a room	with them, and occasionally their constant mischievousness	would	get	on	my	nerves.	They	would	notice the	slightest irritation	and hurry	over	to	fill	my	mouth	with	their	big	hands.	Of	course,	I	never	bit,	but	in	the	Arnhem colony I	have	seen	quite	a few instances	when fingers	were	not treated	so	gently	during appeasement	attempts.	Young	chimpanzees	of three	years	or less,	who	may	have lacked 18 the experience to judge whether the gesture was safe or not, were almost always the victims	of	such	bites.	(80) Vulnerable	contact	behaviour	also	takes	other	forms	amongst	primates.	Once	more	in	the context	of	peace-keeping,	de	Waal	(1989)	describes	the	following	behaviour: [M]ale chimpanzees often finger each other's scrotum at moments of mild tension, a gesture irreverently known among field-workers as ball bouncing. Is there a more convincing	way	of indicating	friendly	intentions	than	by	touching	these	vulnerable	parts? (79) Anecdotal	evidence	also	points	to	the	consolidation	of	alliances	by	means	of	gently	holding another's	testicles	in	other	primates	(e.g.	Balter	2010).	Vulnerable	contact	behaviour	has also	been	witnessed	in	elephants,	who	will	touch	or	put	their	trunk	inside	the	mouth	of	a distressed	conspecific	(Plotnik	and	de	Waal	2014,	12).	A	recent	study	on	captive	orcas	also documents what appears to be vulnerable contact behaviour: the orcas were found to occasionally	put	their	snouts	together,	and	then	one	of	them	would	insert	her	tongue	into the	mouth	of	the	other,	who	would	gently	bite	it.	The	authors	interpret	this	as	an	affiliative gesture	(Sánchez-Hernández	et	al.	forthcoming). Even if we	were to favour a	more intellectualistic notion of trust that excluded these	behaviours from	counting	as	expressions	of	such, these	sorts	of interactions	could still	point	us	to	the	capacity	of	care	or	tact.	A	chimpanzee	holding	another's	testicles	or	an orca biting another's tongue are examples of situations in	which an animal could very easily	hurt	the	other,	but	she	apparently	puts	care	into	making	sure	this	doesn't	happen. And this extends beyond vulnerable contact behaviour. For instance, controlling the strength	with	which	one	bites	during	play	or	carrying	one's	offspring in the	mouth	with the exact pressure needed to hold them without hurting them could also constitute examples	of	animals	exhibiting	care.	To	be	sure,	whether	or	not	these	count	as	instances	of care	or	tact	will	be	a	function	of	the	amount	of	behavioural	flexibility	and	self-control	the animal	has.	If	she	could	not	perform	the	behaviour	any	other	way	then	it	would	not	make sense to say that she is putting care into how she does it. This is not particularly problematic,	however,	since	the	study	of	moral	capacities	in	animals	must	in	any	case	go hand-in-hand	with	the	study	of	animal	self-control	(see	Monsó	and	Andrews	forthcoming). There may be more to learn about the moral capacities of animals if we look further beyond gentle touch. For instance, young animals of various species often play with	each	other	or	with	adults	in	ways	that	can	be	quite	painful.	These	individuals	enjoy enormous	levels	of	tolerance	from	the	older	members	of	the	group.	In	the	case	of	young chimpanzees,	for	instance,	de	Waal	writes:	"They	can	do	nothing	wrong,	such	as	using	the back	of	a	dominant	male	as	a	trampoline,	[...]	or	hitting	an	older	juvenile	as	hard	as	they can" (de	Waal 2014, 189). Tolerance is also a	moral capacity that has not received the 19 attention	it	deserves.	Having	a	young	chimp	use	your	back	as	a	trampoline	or	hit	you	as hard as she can must hurt. If it were an older chimp doing it, this would trigger an aggressive response in return, so it is	possible that there is an inhibition of aggression going on that could also plausibly be regarded	as a	moral capacity. The fact that social tolerance	and	the	inhibition	of	aggression	have	not	been	considered	as	research	topics	in the	animal	morality	debate	highlights	a	bias	towards	moral	capacities	that	are	manifested actively.	But	one	can	also	exercise	a	moral	capacity	by	refraining	from	doing	things. The	ways	in	which	animals	navigate	each	other's	vulnerability	could	thus	give	us evidence of various moral capacities. But what about cases in which the animals purposefully	hurt	each	other?	The	animal	morality	debate	has	until	now	focused	almost exclusively on prosocial behaviour and its underlying	mechanisms.	We suggest that it's also important to look	at	antagonistic and	antisocial interactions in	our search	of	moral capacities	beyond	the	human	species.	Consider	the	following	description	of	an	aggressive altercation	among	captive	chimpanzees: Luit	was	alpha for only ten	weeks. The	Yeroen-Nikkie	alliance	made a	comeback	with	a bloody vengeance one night during	which the two allies together severely injured Luit. Apart from biting off fingers and toes and causing deep gashes everywhere, the two aggressors	removed	Luit's	testicles,	which	were	found	on	the	cage	floor.	Luit	died	on	the operating	table	due	to	loss	of	blood	from	the	fight,	which	took	place	in	a	night	cage	with only	the	three	senior	males	present.	Given	the	victim's	massive	injuries	and	the	relatively few injuries sustained by the other two, we must assume a remarkable level of coordination	between	Nikkie	and	Yeroen.	(de	Waal	1998,	211) To	be	clear,	by	citing	this	example	we	do	not	mean	to	imply	that	this	incident	necessarily amounted	to	a	moral	practice.	Perhaps	Nikkie	and	Yeroen	were	motivated	by	a	non-moral desire to rise in the social hierarchy. But the interaction could have had a moral component	if, for	instance,	Nikkie	and	Yeroen	enjoyed	and	purposefully	prolonged	Luit's suffering. While this single anecdote is far from definitive, the fact remains that chimpanzees	are	capable	of	very	sophisticated	social	cognition	(which	suggests	they	might have	understood	that	Luit	was	suffering)	and	exhibit	high	levels	of	behavioural	flexibility (which suggests a certain degree of control over the way in which the killing was performed).	Thus,	the	extreme	violence	displayed	is	noteworthy	and	justifies	paying	more attention	to	cases	like	this. Lethal intra-specific coalitionary aggression in chimpanzees has also been documented in the	wild, both	within and	outside the instigators' own social group (e.g. Kaburu	et	al.	2013;	Pruetz	et	al.	2017).	Additionally,	non-predatory	inter-specific	killings have	been	witnessed	in	several	mammalian	species.	For	instance,	killer	whales	have	been described to kill narwhal "for fun" in a variety of ways, like drowning, ramming, and mutilating	them,	and	then	"playing	soccer"	with	their	body	parts	(Ferguson	et	al.	2012,	7, 20 11). Bottlenose dolphins have also been observed to harass harbour porpoises, only to brutally	kill	them	and	abandon	their	bodies	(Cotter	2011).	Depending	on	the	behavioural flexibility	manifested in	these interactions, the	social	context	surrounding them,	and the amount of premeditation involved, emotions like cruelty, envy, resentment, schadenfreude,	or	blood	lust	could	be	driving	the	behaviour.	Perhaps	these	emotions	are exclusively human, but this should not be established from the armchair. Not even considering	the	possibility	that	animals	may	also	possess	these	negative	moral	emotions could	also	amount	to	a	distorted	or	partial	account	of	animal	morality. Before	we conclude,	we	would like to	mention how touch can also illuminate a final, very important branch of the animal	morality debate: the study of the normative capacities	of	animals.	Although	animals'	ability	to	follow	and	enforce	normative	standards of behaviour has only begun to be systematically studied in the lab (e.g. by	measuring chimpanzees' spontaneous reactions to videos of infanticide [Rudolf von Rohr et al. 2015]), normativity figures	prominently in	many	accounts of	morality and	much of the work done on the evolution of human morality has focused on the emergence of our normative	capacities	(e.g.	Joyce	2007;	Kitcher	2014;	Tomasello	2016).	In	addition,	Kristin Andrews,	one	of	the	most	prominent	philosophers	in	the	animal	morality	debate,	has	also focused	a	great	deal	of	her	work	on	animal	normativity	(e.g.	Andrews	2009;	2013;	2020). Thus, it is	worth	considering to	what	extent the	study	of touch	can	be illuminating	here too.20	Although	discriminative	and	affective	touch	could	possibly	have	a	role	to	play	in	the enforcement	of	animal	social	norms	(for instance,	discriminative touch	could	be	used to determine	when	an	animal	is	not	playing	'fairly,'	and	affective	touch	could	perhaps	be	used to	reinforce	norm-appropriate	behaviour),	we	believe	that	the	vigilance	function	of	touch is	likely	the	most	relevant	when	it	comes	to	considering	how	touch	can	inform	the	study	of animal	normativity. Following	Andrews (2020),	we assume that an animal social norm	occurs	when "(a)	there	is	a	pattern	of	behavior	demonstrated	by	community	members;	(b)	individuals choose to conform to the pattern of behavior; (c) individuals expect that community members	will	also	conform,	and	will	sanction	those	who	do	not	conform."	We	believe	that a	fruitful	area	of	study	for	uncovering	animal	social	norms	thus	understood	concerns	how animals navigate each other's bodily vulnerability. Looking at how animals touch each other,	when they refrain from touching each other, how they react to others' touch, or when	they	decide	to	intervene	to	stop	others	from	touching	could	illuminate	what	animals consider to	be	appropriate patterns	of behaviour, as	well as to	what extent they expect 20	We	are	grateful	to	an	anonymous	reviewer	for	encouraging	us	to	take	on	this	point. 21 others to	conform	to these	patterns	and	are	motivated to	sanction	nonconformity.	Thus, investigating the touch patterns involved in social play, mating, co-feeding, grooming, infant handling and alloparenting, vulnerable contact behaviour, reconciliation, and consolation could all be	promising	ways	of establishing	whether the animal societies in question	countenance	and	enforce	social	norms. 6.	Conclusion We	have argued that scientists	and	philosophers	have	been	operating	with	a somewhat narrow	view	of	the	set	of	moral	practices	that	animals	could	engage	in,	and	that	bringing the	issue	of	touch	to	the	discussion	has	the	potential	to	uncover	further	moral	practices, while	also	revealing	unnoticed	nuances	in	the	ones	that	are	under	discussion.	Our	defence of the need to pay more attention to touch has been structured as an analysis of the discriminative, affiliative, and vigilance functions of touch. However, it is important to remember that this division is an artificial one: in reality these three functions are intertwined,	and	purposeful	touch	as	an	expression	of	moral	capacities	cannot	be	studied without taking	the	role	of	all	three in	a	specific	context into	consideration.	Moreover,	as also emphasised by Botero, touch as a social medium and its role in animal morality cannot be properly analysed without incorporating field studies. We need to study animals' spontaneous interactions,	and consider their social bonds and social history to assess their	moral capacities	and their	use	of touch, e.g. to	distinguish resentment from mistrust. Lastly, lab conditions, like many other instances of the human-animal relationship,	deprive	animals	of	some	of	the	conditions	they	might	need	to	develop	moral capacities, like parental care or lasting relationships, and thus on their own cannot provide	us	with	a	fair	assessment	of	the	prevalence	and	scope	of	animal	morality. 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