The dating game theory
Reporting in the journal Proceedings of the Royal Society of London B they analysed the function of a courtship gift and what the characteristics of a ‘good’ gift are.
They show that gifts can act as a signal of a man’s intention. Offering an expensive gift may signal a long-term commitment but the man must be wary of being exploited by a gold-digger who intends to dump him once she gets the gift.
By modelling courtship as a sequential game, they show that an extravagant gift, which is costly to the man but worthless to the woman, may solve the problem.
A costly gift signals the man has long-term intentions but by being worthless to the woman, gold-diggers are deterred.[...]
The researchers constructed two versions of the game with different biological assumptions based on whether the male is involved with parental care.
Attractiveness is relevant to human courtship (model 1). Male condition and female receptiveness are the deciding factors in non-parental care species (model 2). In both cases these were represented as binary variables.
Factors in the game such as whether the male and female found each other attractive were given a probability and the possible outcomes of the interaction, either positive or negative for each player, were given scores to represent the consequences of their decisions.[...]
They considered the ‘fitness’ consequences based on a single courtship encounter involving a male and female. Despite the different biological assumptions, the two models had the same underlying mathematical structure, with both yielding equilibrium solutions in which males predominantly offer costly but worthless gifts as a prelude to mating.
Journal: Proceedings of the Royal Society of London B
Title: ‘Costly but worthless gifts facilitate courtship’
Authors: Peter Sozou, Robert Seymour
UCL’s Centre for Mathematics and Physics in the Life Sciences and Experimental Biology, University College London, Gower Street, London, WC1E 6BT