Deficits in the social approach exhibited in mice models of mental disorders, such as autism 10, depression 11, schizophrenia 12, and anxiety disease 13. Social approach behaviour was measured initially by observing mice interacting freely in an open field 8 and later in a three-chambered assay 9. Similarly to humans, many non-human animals exhibit a natural tendency to approach and investigate unfamiliar conspecifics, as reported in fish 5, mouse 6, and rat 7. Such an understanding would also help to elucidate how complex features, such as emotions and desires, emerge from networks of neurons in general. Understanding sociality and related disorders require a clear understanding of the evolutionary roots and neural substrate of the desire for social affiliation.
Moreover, social motivation deficits are common phenomena in mental disorders, including autism, depression, and anxiety disorder 1, 2, 3, 4. In social animals, individuals in a population tend to associate in groups, and, in the case of humans, form cooperative societies. Social affiliation is a fundamental behaviour in many species.
