Aron and colleagues investigated whether interpersonal closeness can be deliberately generated through structured self-disclosure. Pairs of previously unacquainted students were randomly assigned to one of two conditions. In the closeness condition, partners worked through a set of questions that gradually escalated in personal depth, taking turns to answer and disclosing increasingly personal information and feelings. In the control condition, partners answered small-talk questions of similar length. After about 45 minutes, participants in the escalating self-disclosure condition reported feeling significantly closer to their partner than those in the small-talk condition. The researchers concluded that mutual, escalating self-disclosure can rapidly increase feelings of closeness between strangers, highlighting the role of reciprocal disclosure in the formation of relationships.

References: Aron, A., Melinat, E., Aron, E. N., Vallone, R. D. and Bator, R. J., 1997. 'The experimental generation of interpersonal closeness: a procedure and some preliminary findings.' Personality and Social Psychology Bulletin, 23(4), pp. 363 to 377. source adapted.

People often end up with partners whom others rate as fairly similar to them in physical attractiveness, rather than with the most attractive person available.

Seeing a stranger in pain, a person feels a strong urge to help. Brain regions that are active when we feel pain ourselves are also active when we watch others in pain.

Piliavin and colleagues investigated what affects whether people help a stranger. In a field experiment on a New York subway train, a member of the research team staged a collapse shortly after the train left a station. Across trials, the 'victim' appeared either ill (carrying a cane) or drunk (smelling of alcohol and carrying a bottle). Observers recorded how often, how quickly, and by whom help was given, while other passengers were unaware that the situation was staged. The apparently ill victim was helped quickly and often, whereas the apparently drunk victim was helped less and more slowly. Unlike many laboratory bystander studies, help was frequently given even when many passengers were present. The researchers linked helping to the perceived cost of helping and the type of victim, rather than simply to the number of bystanders.

References: Piliavin, I. M., Rodin, J. and Piliavin, J. A., 1969. 'Good samaritanism: an underground phenomenon?' Journal of Personality and Social Psychology, 13(4), pp. 289 to 299. source adapted.