Talking to someone or buying someone a drink. Electricity, telephones, cars and other items of utility are markers discovered, invented or created by males. A female marks a male by choosing or mending his clothes. Primordial marking is leaving scent. Other forms of territorial marking are decorating a flat or leaving something at a table intending to return.
Hints are commonplace examples of the token.
A token has different values for the giver and the receiver. Calling someone s name, having an arrangement to meet, being able to touch or hold someone or being married. Females prefer signals and tokens because they are ambiguous and therefore manipulative, while males prefer markers and handles because they are unambiguous and often involve the wealth which he creates. The Prisoner s Dilemma is a basic model in biology, used to model and predict the behaviour of many animal species. The PD has been applied to insects, lizards and fish, to name but a few.