One view of how social identity impacts choice is that it is driven by a fixed individual propensity to be attached to an identity and only individuals who are "groupy" are predicted to have high attachment to a social identity.

A contrasting view is that people are not "groupy" but rather that the propensity to be attached to an identity waxes and wanes. The aim of this project is to experimentally test two competing conceptualisations of how identity attachment determines choice.

There are currently two established views on social identity attachment that this project explores:

• The view that a person's decision making is driven by a fixed individual propensity, a "groupy trait", to be attached to an identity.
• The view that "strength-of-attachment" to social identity waxes and wanes. This would predict that attachment can be strengthened or weakened in predictable ways and that the impact of social identity on choice will wax and wane as attachment does.

Testing the "strength-of-attachment" conceptualisation has considerable and important implications for how we model and craft policy-interventions that leverage social identity motivated behaviour. If such phenomena as in-group favouritism are derived from attachment to group identity (and less from an individual "groupy trait" to be attached), then, and only then, does it make sense to attempt to alter identity-motivated choice through framing our choices or creating policy interventions that alter the stories or narratives we tell.
Further, the "strength-of-attachment" view has implications for the development of theory and the design of new methodologies for testing theories.