7. Same Sex Aggression- Challenge hypothesis Flashcards Preview

human evolution > 7. Same Sex Aggression- Challenge hypothesis > Flashcards

Flashcards in 7. Same Sex Aggression- Challenge hypothesis Deck (42)
Loading flashcards...

evidence for 6.1 testosterone mating versus paternal effort

• Burnham et al., 2003 reported than young unpaired men had higher T levels than unmarried men in committed romantic relationships, who had similar levels to those of unmarried men without children.
• In a sample of over 4462 military veterans, testosterone levels were positively associated with not marrying and with marital instability, and negatively with measures of marital quality, such as spending less time with their wives, and more extra-marital sex (Dabbs and Morris, 1990)


evidence for 6.2 testosterone and antisocial activities

• Using data from the large sample of military veterans, Dabbs et al. (1990) did find an association between testosterone levels and an antisocial personality, alcoholism and drug use (DSM-III criteria), although the magnitude was small. In an analysis of the same sample, Dabbs and Morris (1990) found that those with the top 10% testosterone levels were higher on antisocial activities including assaults than the remaining sample.
• Stanford et al., 2003- One characteristic that is often associated with heightened aggression is impulsivity.
• In review Archer (2006) says that from a number of studies looked at- It is likely that testosterone is associated with uninhibited, risk-taking, behavior that fits men poorly for achievement in higher-status occupations in organizations


evidence for 6.3 personality and behavioral characteristics

• Underlying the associations between testosterone and characteristics associated with preferences for shorter-term mating strategies and more uninhibited behavior there should be a comparable link between testosterone and personality profiles, and also with behavior associated with personality characteristics.
• Daitzman and Zuckerman (1980) found higher testosterone levels among 20 young men with high disinhibition scores than those with low disinhibition scores.


evidence for 6.4 are these factors associated with life history strategies

• If the associations between testosterone and the characteristics reviewed in Sections 9 and 10 are associated with alternative life history strategies, it is likely that they will be present early in life, before puberty.
• Archer (2006) meta-analysis association between T and aggression occurs in males but not in females in childhood.
• These findings suggest that high and low testosterone males may tend to set out on different life courses equivalent to alternative life history strategies, and that these differences are apparent from relatively early ages, at least well before puberty. How these individuals progress will of course depend on how their social circumstances interact with their dispositions. Evidence from the large-scale study of US military veterans indicates that associations between testosterone and overt antisocial activity, and with occupational status, are accentuated by living in a low social class environment, and attenuated by living in a higher social class environment. Overall the evidence indicates an association of these life history strategies with testosterone levels and that the association is found before puberty for boys.


what in conclusion can be said about the challenge hypothesis?

• Challenge hypothesis has a sounder basis in ET than the ‘mouse model’ which supposes a straightforward influence of testosterone on aggression in males from puberty onwards


what is adaptive about the challenge hypothesis?

As a result, of the costs of high levels of testosterone, it would be adaptive to avoid maintaining consistently high levels throughout adulthood. Thus, if testosterone can be kept relatively low, and yet still support reproductive physiology and behavior, this will be more adaptive than maintaining consistently high levels. Further, if levels can be raised under conditions of reproductively-related competition, when behavior associated with a rise in testosterone is required, this again would be more adaptive than maintaining consistently high levels. Thus, the challenge hypothesis essentially involves an adaptive mechanism that avoids the high costs of testosterone (Wingfield et al., 2001).


what improvements could be made with research into T

A further point that could be important in future studies concerns individual differences in the sensitivity of receptors to the action of testosterone (Manning et al., 2003). Taking into account receptor sensitivity may yield higher associations between testosterone and behavioral variables than is apparent in existing studies.


what did wingfield note about female T

• Although the challenge hypothesis is concerned with males, Wingfield et al. (2000) did note that there was considerable variation in testosterone levels between females of different bird species.


what can be said overall about the challenge hypothesis and females?

Some similarities with T to males but seem this may be more to do with protection of children as opposed to fighting for mate choice as much


when are T levels more pronounced in females of a species?

• When sexual dimorphism was less pronounced, as in monogamous species, testosterone levels of females relative to those of males are higher, and it is possible that testosterone may be involved in female competition.


what studies indicate that T may play a role in aggression for females?

o Amongst others
o The association between testosterone and aggression was found to be higher for female than male samples (Archer et al., 2005).
o Van Honk et al., 2001- when T administered to young women there were heightened reflexes to angry faces, which was attributed to the hormone facilitating dominance behaviour.
o A further study showed that women with higher androgen levels had higher occupational status, possibly as a result of their being more assertive (Baucom et al., 1985)


what do findings of female T levels suggest/ support?

• All these studies indicate that women may respond with increased testosterone to challenging situations, and that they show similar correlations between testosterone and personality characteristics such as aggressiveness and dominance.
• This finding fits the suggestion (Wingfield et al., 2000) that in species where sexual dimorphism is less pronounced, and there is more paternal care, testosterone plays an important part in female competition for resources, and for males and their parental investment