Evolutionary Perspective Of Metaphor Bias In A Mating Context: Modulatory Effects Of Hormones

The evolutionary origins of language remain a conundrum although natural selection in accordance with Darwinian theory is the prevailing view.The development of human language has clearly required both peripheral(vocal organs)and brain adaptations.While we have increasing understanding of the neural mechanisms controlling both language production and comprehension,the central question of what the key factors were to promote their evolution remains an enigma.For example,is language a product of our ancestors’ needs for social interaction or cooperation for survival purpose,or merely a by-product of the evolution of mental faculties? If its roots lie in the need for more effective social interaction,what kind of specific interpersonal communication requirement might act to drive language to evolve initially and then develop in its sophistication across generations? Furthermore,what biological structures have evolved to support language evolution and development and how do they regulate its use in specific contexts? To date,there are very few research findings.Therefore this research aims to explore whether or not “Scheherazade Hypothesis” of sexual selection might have been contributed to language evolution through focusing specifically on the use of metaphorical language in the context of mate choice.Additionally,the evolutionary conserved hormones known to influence inter-sex communication,sexual attraction and mate choice – estrogen,testosterone and oxytocin – have been investigated in the context of the use,impact and neural processing of metaphorical language in courtship.Study 1 investigated whether or not women preferred men to pay compliments in a mating context using a metaphorical language form,and if this perference varied across their menstrual cycle.The results showed for the first time that women preferred the men who used metaphorical rather than literal expression to complement their appearance.Moreover,women in a relationship preferred novel metaphor compliments during their fertile phase whereas single women did so during their luteal phase.Lastly,the men who used metaphorical compliments gave women lasting positive impression.Being in position of choosers in mate selection,women’s metaphor preference is not only to select a good gene carrier for offspring,but also likely to cause male competition in metaphor creation that requires brain mentality indeed,thereby propelling cognitive intelligence in return.Study 2 specifically examined whether men’s use of metaphor for paying compliments to women in a mating context might be used as a covert signal of their quality as a potential mate,particularly with respect to their creativity and intelligence.The results firstly demonstrated that when interacting with women a mating context as opposed to a working context,men exhibited a stronger motivation to produce metaphorical compliments,thus producing more and higher quality metaphorical compliments,and the number produced was correlated with men’s art creativity and prenatal testosterone(as indexed by their hand 2D4 D ratio).Women preferred to have a date with those who produced more metaphorical compliments targeting their appearance.Interestingly,women could infer men’s verbal intelligence merely through the metaphorical compliments they produced in a mating,but not working,context.Being in position of wooers in mate selection,the relation between men’s metaphor production and mate qualities in a mating context suggests that metaphor creation must have a certain advantage in male competition,which is a mental difficulty that is hard to counterfeit.It becomes prominent and inherited by winning more female mates in mate selection.Thus,overall studies 1 and 2 support the possibility that the evolution of complex language has been influenced to some extent by its use to attract mates through advertising mate quality.In this way,individuals with greater language skills would have an advantage for reproducing their genes,thereby helping to drive language evolution.In a third study,the possible modulatory effects of oxytocin on the responses of women to metaphors in a mating context and on language circuitry in the brain were investigated at different stages of the menstrual cycle in a within-subject,randomized double-blind placebo controlled behavior and functional magnetic resonance imaging(fMRI)paradigm.Women subjects therefore received the same oxytocin(24 IU)or placebo treatment twice,once in the fertility phase and once in the luteal phase of menstrual cycle while they completed tasks in an MRI scanner.Results showed that in a mating context,oxytocin reduced the attractiveness of the men producing metaphorical compliments for women in their fertile phase.Correspondingly,there was an activation in dorsal anterior cingulate cortex but reduction in the functional connectivity between dorsal anterior cingulate cortex and orbitofrontal gyrus.This finding indicates that estrogen and oxytocin may have opposite effects in regulating mate selection in women during their fertile phase.The anterior cingulate cortex is an important part of the brain salience network and involved into decision-making.A number of previous studies have reported oxytocin effects of dorsal anterior cingulate cortex activity and functional connectivity.It is possible that oxytocin is acting to enhance the appraisal sensitivity towards social compliments,but to inhibit the rewarding value of men’s metaphorical compliments for women during their fertile phase,since these sentences may communicate sexual rather than bonding interest.Other research has reported that oxytocin increases interest more in words related to positive relationships and bonding.Further research is required to investigate this possibility.In conclusion,the above studies have tested and explored the possibility that sexual selection has contributed to the evolution of complex language forms such as metaphors and possible modulatory effects of sex hormones and oxytocin.Overall,findings support this possibility with metaphor production and quality produced by men in a mating context both being more attractive to women and also capable of signaling mate quality.Women’s behavioral and brain responses to metaphorical compliments targeting appearance may be modified differentially by sex hormones,which tend to promote sexual interest,and oxytocin,which is more related to the promotion of romantic bonds.More generally,these studies have increased our understanding of the origins of the prolific use of metaphorical expressions in poetry and literature,etc.,which can successful communicate creativity,emotion and romance.They have also helped to explain why such complex and potentially ambiguous forms of language communication are so commonly used.From both psychological and neurobiological viewpoints,these studies have delved into pragmatic strategies used in heterosexual romantic communication and opened up a new orientation for understanding language evolution.