Recent years have seen an upsurge of attention paid to street gangs as scholars and criminal justice officials strive to understand and counteract the effects of gang membership. Yet, despite a wealth of theoretical frameworks and empirical findings, even fundamental issues such as an agreed definition continue to elude us. We consider some of the most influential theoretical frameworks and associated empirical findings and find that as it stands, our knowledge on gangs is still limited and rather muddy. We suggest that future directions should adopt a more multidisciplinary approach to the study of gangs. To this end, we argue that there is a role for psychology in this important body of work, and that its involvement will provide us with a deeper and more meaningful understanding of gangs and the youth who join them. 3 Running head: Street gangs theory research