Conformity is a change in behaviour or belief as a result of group or imagined pressure. One study into conformity would be Sheriff's study (1935). In this he aimed to investigate the development of group norms and conformity into those norms. He did this by using the autokinect effect. This is where a spot of light is shown in a dark room and appeared to move around. The autokinect was first shown to pps as individuals and then in a group and then reversed so the group was show first and then as an individual. Sheriff concluded from this that when faceed with an ambiguous situation, people turn to others for guidance and that people will adjust their own judgment to be similar to others'. Also, people internalise group norms and make them their own.
Another study into conformity would be from Asch (1951). The aim of the study was to see if people would conform even if they knew the majority was wrong. Asch placed card on a table - one with the standard line and the other with comparison lines. Pps then were asked to state which of the comparison lines was the same as the standard. The conferederates were then to say the wrong answer. Asch concluded from this study that the pps behaviour was a case of public compliance and the findings show the power of majority influence.
One strenghth of Sheriff's study was that it was a labratory experiment. This means all variables can be controlled and any extrenuous variables can be isolated from the study. In turn this creates a causal relationship where any effect on the DV is only due to the IV increasing the study's internal validity. One weakness of Sherif's study is that it may lack cross cultural validity as the research was carried out in an individualistic culture, the USA, meaning the findings of the study may not be generalisable to the wider population decreasing the studies external validity.
A weakness of Asch's study would be in population validity....