Evaluate the collective function of references cited together in a given text segment.
Classify their combined role into one of the following categories: 'method', 'background', or 'result'.

Text:…have long regarded attitudes towards AAP beneficiaries and non-beneficiaries as related, but ultimately separable, and evidence supports that attitudes toward the in-group and the out-group have independent effects on individuals’ reactions to AAPs (Harrison et al., 2006; Lowery et al., 2006).
Category: