In wild animal populations, the adaptive function of tool use behaviour is posited or assumed, but rarely tested, either because tracking the spread of behaviours is challenging or all individuals in a population engage in the tool using behaviour.
However, even when such information is not available, we can use the wealth of available knowledge on qualitative properties of networks and how these relate to the spread of behaviours.
Here we describe a novel method that allows social and asocial learning to be distinguished inferentially, in animal datasets that record the spread of novel behaviour patterns.
After an initial spread of a behaviour throughout a group, this mechanism may lead to a superficial appearance of conformity without the involvement of such a socially and cognitively complex mechanism.
The contagious role of media in the alleged endemic spread of destructive behaviour has been debated in connection with school shootings in the US [ 4, 5].
Given that ego-alter homogeneity has been shown to be predictive of the spread of a behaviour between two individuals, we would also expect that there will be a stronger association between ego-alter health behaviours for individuals who are similar in terms of their migration background.
After the innovation and initial spread of a novel behaviour, the behaviour stabilizes and is maintained over time.
Notes: 1) OR = odds ratio; the OR range is calculated as the range between exp -1.29*τ exp -1.29*τ29*τ); 2) FP = fandly practicexp3) The variance τ2 estimated in the random effects model is a measure of the between-FPs differences, and indicated the spreading of prescribing behaviour of the individual FPs; 4) CVD = cardiovascular disease.
These interaction theories have been labeled contagion and convergence theories, respectively the former stressing the contagious spread of mood and behaviour; the latter stressing the convergence of a large number of people with similar predispositions.
Given the subsequent spread of the strange behaviour to other girls and young women in the community and the timing of its display, however, those physiological and psychological explanations are not very convincing.
