Complex Relations Between Psychopathy and Fitness May Indicate Adaptive Trade-Offs

Abstract

In order to assess the potential of psychopathy to increase evolutionary fitness, we examined the relations between psychopathy and fitness indicators (number of children and grandchildren, problems in physical health both in parents and offspring) in a sample of post-reproductive individuals (N = 187; M_age = 66.52). Specifically, we explored the possibility that psychopathy traits are involved in evolutionary trade-offs: both positive and negative relations with different fitness components. Psychopathy was measured via three traits—interpersonal, affective, and lifestyle characteristics, which are operationalized by proxy scales derived from the HEXACO-PI-R inventory. Research findings showed that interpersonal traits were positively related to the number of children and negatively to the number of grandchildren and problems in physical health; lifestyle characteristics were positively associated with problems in physical health in participants’ offspring. The data are in line with previous studies which explored the relations between psychopathy and fitness. The findings extend on previous studies by suggesting that psychopathy may be involved in evolutionary trade-offs, especially the quantity-quality trade-off. These trade-offs may in return maintain inter-individual variation in psychopathy.

Appendix

HEXACO-PI-R items used for the construction of the psychopathy scales (Međedović 2017a). The symbol “(R)” suggests that the item is reversely coded; the names of HEXACO factors to which the items originally belong and their numbers in HEXACO-PI-R are provided in parenthesis as well.

Interpersonal

If I want something from a person I dislike, I will act very nicely toward that person in order to get it. (Honesty; no. 6).

My attitude toward people who have treated me badly is “forgive and forget”. (R) (Agreeableness; no. 27).

I would be tempted to buy stolen property if I were financially tight. (Honesty; no. 36) I would like to live in a very expensive, high-class neighborhood. (Honesty; no. 42).

I wouldn’t want people to treat me as though I were superior to them. (R) (Honesty; no. 48).

If I want something from someone, I will laugh at that person’s worst jokes. (Honesty; no. 54).

I would never accept a bribe, even if it were very large. (R) (Honesty; no. 60).

When people tell me that I’m wrong, my first reaction is to argue with them. (Agreeableness; no. 63).

I would like to be seen driving around in a very expensive car. (Honesty; no. 66).

I think that I am entitled to more respect than the average person is. (Honesty; no. 72).

I find it hard to fully forgive someone who has done something mean to me. (Agreeableness; no. 75).

I wouldn’t pretend to like someone just to get that person to do favors for me. (R) (Honesty; no. 78).

I’d be tempted to use counterfeit money, if I were sure I could get away with it. (Honesty; no. 84).

I would get a lot of pleasure from owning expensive luxury goods. (Honesty; no. 90).

I find it hard to keep my temper when people insult me. (Agreeableness; no. 93).

I want people to know that I am an important person of high status. (Honesty; no. 96).

People sometimes tell me that I’m too stubborn. (Agreeableness; no. 15).

If someone has cheated me once, I will always feel suspicious of that person. (Agreeableness; no. 51).

Affective

People sometimes tell me that I am too critical of others. (Agreeableness; no. 9).

I avoid making “small talk” with people. (Extraversion; no. 16).

When I suffer from a painful experience, I need someone to make me feel comfortable. (R) (Emotionality; no. 17).

I feel like crying when I see other people crying. (R) (Emotionality; no. 23).

I wouldn’t spend my time reading a book of poetry. (Openness; no. 25).

I can handle difficult situations without needing emotional support from anyone else. (Emotionality; no. 41).

When someone I know well is unhappy, I can almost feel that person’s pain myself. (R) (Emotionality; no. 47).

I feel that I am an unpopular person. (R) (Extraversion; no. 52) I tend to be lenient in judging other people. (R) (Agreeableness; no. 57).

Whenever I feel worried about something, I want to share my concern with another person. (R) (Emotionality; no. 65).

People often tell me that I should try to cheer up. (Extraversion; no. 70).

I feel strong emotions when someone close to me is going away for a long time. (R) (Emotionality; no. 71).

Even in an emergency, I wouldn’t feel like panicking. (Emotionality; no. 77).

I rarely discuss my problems with other people. (Emotionality; no. 89).

I remain unemotional even in situations where most people get very sentimental. (Emotionality; no. 95).

I have sympathy for people who are less fortunate than I am. (R) (Altruism facet; no. 97).

I try to give generously to those in need. (R) (Altruism facet; no. 98).

People see me as a hard-hearted person. (Altruism facet; no. 100).

Lifestyle

I would feel afraid if I had to travel in bad weather conditions. (R) (Emotionality; no. 5).

If I knew that I could never get caught, I would be willing to steal a million dollars. (Honesty; no. 12).

I make decisions based on the feeling of the moment rather than on careful thought. (Conscientiousness; no. 20).

People think of me as someone who has a quick temper. (Agreeableness; no. 21).

I plan ahead and organize things, to avoid scrambling at the last minute. (R) (Conscientiousness; no. 26).

I don’t mind doing jobs that involve dangerous work. (Emotionality; no. 29).

People often joke with me about the messiness of my room or desk. (Conscientiousness; no. 50).

I often push myself very hard when trying to achieve a goal. (R) (Conscientiousness; no. 32).

I make a lot of mistakes because I don’t think before I act. (Conscientiousness; no. 44).

When it comes to physical danger, I am very fearful. (R) (Emotionality; no. 53).

Often when I set a goal, I end up quitting without having reached it. (Conscientiousness; no. 56).

I think of myself as a somewhat eccentric person. (Openness; no. 67).

I don’t allow my impulses to govern my behavior. (R) (Conscientiousness; no. 68).

When working, I sometimes have difficulties due to being disorganized. (Conscientiousness; no. 74).

I do only the minimum amount of work needed to get by. (Conscientiousness; no. 80).

I prefer to do whatever comes to mind, rather than stick to a plan. (Conscientiousness; no. 92).

It wouldn’t bother me to harm someone I didn’t like. (Altruism facet; no. 99).