Editing Handicap principle (section)

=== Immunocompetence handicaps ===

The theory of [[immunocompetence]] handicaps suggests that [[androgen]]-mediated traits accurately signal condition due to the [[Immunosuppression|immunosuppressive]] effects of androgens.<ref>{{cite journal |last1=Folstad |first1=I. |last2=Karter |first2=A. K. |year=1992 |title=Parasites, bright males, and the immunocompetence handicap |journal=American Naturalist |volume=139 |issue=3 |pages=603–622 |jstor=2462500 |doi=10.1086/285346|s2cid=85266542 }}</ref>  This immunosuppression may be either because [[testosterone]] alters the allocation of limited resources between the development of [[Secondary sex characteristic|ornamental traits]] and other tissues, including the [[immune system]],<ref>{{cite journal |last1=Wedekind |first1=C. |last2=Folstad |first2=I. |year=1994 |title=Adaptive or non-adaptive immunosuppression by sex hormones? |journal=American Naturalist |volume=143 |issue=5 |pages=936–938 |jstor=2462885 |doi=10.1086/285641|s2cid=84327543 }}</ref> or because heightened immune system activity has a propensity to launch autoimmune attacks against [[gametes]], such that suppression of the immune system enhances [[fertility]].<ref>{{cite journal |last1=Folstad |first1=I. |last2=Skarstein |first2=F. |year=1996 |title=Is male germ line control creating avenues for female choice? |journal=[[Behavioral Ecology (journal)|Behavioral Ecology]] |volume=8 |issue=1 |pages=109–112 |doi=10.1093/beheco/8.1.109 |doi-access=free }}</ref> Healthy individuals can afford to suppress their immune system by raising their testosterone levels, at the same time augmenting secondary sexual traits and displays. A review of empirical studies into the various aspects of this theory found weak support.<ref>{{cite journal |last1=Roberts |first1=M. L. |last2=Buchanan |first2=K. L. |last3=Evans |first3=M. R. |year=2004 |title=Testing the immunocompetence handicap hypothesis: a review of the evidence |journal=Animal Behaviour |volume=68 |issue=2 |pages=227–239 |doi=10.1016/j.anbehav.2004.05.001 |s2cid=9549459 }}</ref>