Sex differences in emotional behaviour: A reply to Gray and Buffery

Criticism is made of Gray's theory that female rodents are more fearful than males and of the inferences Gray, and Gray and Buffery made concerning the adaptive significance of sex differences, particularly with regard to ‘fear’.

Abstract

A number of specific criticisms are made of Gray's theory that female rodents are more fearful than males: first, measures from the tests he cited are not related in a way which is adequately described by a unitary concept; secondly, sex differences in ‘fear’ measured by these different tests are not controlled by the same set of hormonal factors in each case; thirdly, sex differences in open field measures are more variable than Gray suggested; fourthly, an alternative view of sex differences in avoidance conditioning is presented, which accounts more adequately for recent work involving sex hormones and which is difficult to explain using a ‘fearfulness’ hypothesis; fifthly, alternative explanations are presented for inferences made from sex differences in corticosterone levels, and in response to crowding. More general criticisms are made of the inferences Gray, and Gray and Buffery made concerning the adaptive significance of sex differences, particularly with regard to ‘fearfulness’. Certain crucial assumptions of their theory are questioned: (1) that hormonal effects on behaviour are most usefully considered in terms of major motivational variables; (2) that all hormonally-produced sex differences are the result of direct effects of the hormone on the CNS; (3) that such sex differences are relatively fixed genetic characteristics; (4) that ‘dominance’ and WYNNE-EDWARDS' (1962) theory of population control can provide an adequate foundation for a general theory of sex differences.