one strength of free will is that it has practical value. Roberts et al. looked at adolescents who has a strong belief in fatalism- that their lives were 'decided' by events outiside of their control. They were at greater risk if developing depression. People who exhibit an internal, rather than external, locals of control are more likely ti be optimistic. This suggests that, even if we do not have free will, the fact that we believe we do may have a positive impact on mind and behaviour