This was the common belief at this time "research such as Lorenz" (1974 cited in Brown 2007) put forward a biological theory arguing that conflict could be explained in terms of intrinsic aggressive instincts Tajfel believed that this 'blood and guts' model as he coined them did not account for the waxing and waning of political conflicts throughout the world. The social aspect was studied from the point of view of how it affected the individual and these theories; Brown (2007) suggests were further evidenced by staged unrealistic experimental studies. The work of Tajfel and Turner wanted to move away from the dominant experimental position which they believed lacked validity as it took no account of intergroup relations in a social context or considered any broader cultural and historical factors. The irony of this is that social identity theory came about initially through Henri Tajfel's experimental laboratory based research on social perception which highlighted cognitive biases. His results suggested that people overestimate the physical difference of high and low value coins and underestimated the size difference of similar valued coins. .
Tajfel argued (1969 cited in Brown 2007) that these cognitive biases might translate to how we perceive other people and how we categorise groups in terms of nationality, ethnicity and socioeconomic status. These biases would become the core of social identity theory as Tajfel argued that we see similarities in people we perceive that belong together and over exaggerate the differences between groups. Tajfel believed this categorisation process was at the heart of all prejudice. He wanted to develop an approach to research that would incorporate cognitive intergroup processes with a more social approach which would take into account the social, cultural and economic variables so often overlooked in the experimental approach per se.