Limits...
Fitness Costs Predict Emotional, Moral, and Attitudinal Inbreeding Aversion

View Article: PubMed Central - PubMed

ABSTRACT

In terms of sexual intercourse, the very last people we think about are our kin. Imagining inbreeding intercourse, whether it involves our closest kin or not, induces aversion in most people who invoke inbreeding depression problems or cultural considerations. Research has focused on the disgust felt when facing inbreeding intercourse between close kin but little is known about other responses. In this study, we considered the influence of fitness costs on aversive reactions by including disgust and emotional reaction as well as moral judgment and attitudes toward inbreeding: higher costs should induce a stronger aversive reaction. The fitness costs were manipulated by two factors: (i) the degree of the participants' involvement in the story (themselves, a sib or an unknown individual), and (ii) the degree of relatedness between the two inbreeding people (brother/sister, uncle-aunt/niece-nephew, cousin). To test this hypothesis, 140 women read and assessed different inbreeding stories varying in the fitness costs incurred. Findings showed that the higher the fitness costs were, the greater the aversive reaction was in an overall way. First, our results fitted with previous studies that tested the influence of fitness costs on disgust. Second, and more interestingly, findings went further by examining overall aversion, showing that fitness costs could influence emotions felt as well as attitudes and behaviors toward inbreeding people. The higher the fitness costs were, the less inbreeding people were perceived as moral and the more they were considered as a nuisance. However, results regarding avoidance were more nuanced.

No MeSH data available.


Influence of the degree of relatedness on aversive reactions (log of the odds-ratio, LOR and 95% confidence interval CI; the “avoidance” measure is a reversed one). The degree of relatedness implies 3 ordinal modalities: brother/sister (r = 0.5), uncle-aunt/niece-nephew (r = 0.25) and cousins (r = 0.125) intercourse. If LOR = 0: the degree of relatedness does not affect the odds of outcome; LOR > 0: the degree of relatedness is associated with higher odds of outcome; LOR < 0: the degree of relatedness is associated with lower odds of outcome. *p < 0.05; **p < 0.005.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC5121126&req=5

Figure 2: Influence of the degree of relatedness on aversive reactions (log of the odds-ratio, LOR and 95% confidence interval CI; the “avoidance” measure is a reversed one). The degree of relatedness implies 3 ordinal modalities: brother/sister (r = 0.5), uncle-aunt/niece-nephew (r = 0.25) and cousins (r = 0.125) intercourse. If LOR = 0: the degree of relatedness does not affect the odds of outcome; LOR > 0: the degree of relatedness is associated with higher odds of outcome; LOR < 0: the degree of relatedness is associated with lower odds of outcome. *p < 0.05; **p < 0.005.

Mentions: We then tested the influence of the degrees of involvement and relatedness on the general aversive reaction to inbreeding. According to the first prediction, the closer the participants are to the individuals involved, the greater the aversion would be. Effectively, the degree of involvement had a significant effect on each dependent variable except the moral aspect (see Table 1 for main effects and Figure 1 for contrasts). As expected, the higher the degree of involvement was, the higher the scores of negative emotions and nuisance were. Unexpectedly, when the degree of involvement was higher, participants avoided inbreeding people less. According to the second prediction, the closer the inbreeding people are, the greater the aversion would be. Effectively, the degree of relatedness had a significant effect on each dependent variable except avoidance (see Table 2 for main effects and Figure 2 for contrasts). As expected, the higher the degree of relatedness was, the higher the scores for negative emotions and nuisance were, and the lower the moral judgment score was.


Fitness Costs Predict Emotional, Moral, and Attitudinal Inbreeding Aversion
Influence of the degree of relatedness on aversive reactions (log of the odds-ratio, LOR and 95% confidence interval CI; the “avoidance” measure is a reversed one). The degree of relatedness implies 3 ordinal modalities: brother/sister (r = 0.5), uncle-aunt/niece-nephew (r = 0.25) and cousins (r = 0.125) intercourse. If LOR = 0: the degree of relatedness does not affect the odds of outcome; LOR > 0: the degree of relatedness is associated with higher odds of outcome; LOR < 0: the degree of relatedness is associated with lower odds of outcome. *p < 0.05; **p < 0.005.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5121126&req=5

Figure 2: Influence of the degree of relatedness on aversive reactions (log of the odds-ratio, LOR and 95% confidence interval CI; the “avoidance” measure is a reversed one). The degree of relatedness implies 3 ordinal modalities: brother/sister (r = 0.5), uncle-aunt/niece-nephew (r = 0.25) and cousins (r = 0.125) intercourse. If LOR = 0: the degree of relatedness does not affect the odds of outcome; LOR > 0: the degree of relatedness is associated with higher odds of outcome; LOR < 0: the degree of relatedness is associated with lower odds of outcome. *p < 0.05; **p < 0.005.
Mentions: We then tested the influence of the degrees of involvement and relatedness on the general aversive reaction to inbreeding. According to the first prediction, the closer the participants are to the individuals involved, the greater the aversion would be. Effectively, the degree of involvement had a significant effect on each dependent variable except the moral aspect (see Table 1 for main effects and Figure 1 for contrasts). As expected, the higher the degree of involvement was, the higher the scores of negative emotions and nuisance were. Unexpectedly, when the degree of involvement was higher, participants avoided inbreeding people less. According to the second prediction, the closer the inbreeding people are, the greater the aversion would be. Effectively, the degree of relatedness had a significant effect on each dependent variable except avoidance (see Table 2 for main effects and Figure 2 for contrasts). As expected, the higher the degree of relatedness was, the higher the scores for negative emotions and nuisance were, and the lower the moral judgment score was.

View Article: PubMed Central - PubMed

ABSTRACT

In terms of sexual intercourse, the very last people we think about are our kin. Imagining inbreeding intercourse, whether it involves our closest kin or not, induces aversion in most people who invoke inbreeding depression problems or cultural considerations. Research has focused on the disgust felt when facing inbreeding intercourse between close kin but little is known about other responses. In this study, we considered the influence of fitness costs on aversive reactions by including disgust and emotional reaction as well as moral judgment and attitudes toward inbreeding: higher costs should induce a stronger aversive reaction. The fitness costs were manipulated by two factors: (i) the degree of the participants' involvement in the story (themselves, a sib or an unknown individual), and (ii) the degree of relatedness between the two inbreeding people (brother/sister, uncle-aunt/niece-nephew, cousin). To test this hypothesis, 140 women read and assessed different inbreeding stories varying in the fitness costs incurred. Findings showed that the higher the fitness costs were, the greater the aversive reaction was in an overall way. First, our results fitted with previous studies that tested the influence of fitness costs on disgust. Second, and more interestingly, findings went further by examining overall aversion, showing that fitness costs could influence emotions felt as well as attitudes and behaviors toward inbreeding people. The higher the fitness costs were, the less inbreeding people were perceived as moral and the more they were considered as a nuisance. However, results regarding avoidance were more nuanced.

No MeSH data available.