Little is known about psychosocial or ‘internal’ behaviours that can perpetuate chronic poverty and how to alleviate them in development programmes. This paper presents a conceptual and evaluation framework examining the relationship between a person's psychosocial behaviours, empowerment and economic wellbeing. The framework shows empowerment is enabled or limited by internal behaviours – including one's identity, aspiration, hope and confidence. We tested the framework on a behaviour change intervention among 1508 extremely poor smallholder farmers in Zambia. The intervention was a six‐session curriculum for promoting positive mindsets using faith‐based messages. We used concurrent mixed methods to examine changes and differences in levels of empowerment for individuals exposed to the intervention and those not. We found significant correlations between participation in the intervention and improvements in participants' internal attitudes and overall empowerment. The framework and mixed methods evaluation offer insights into how to design programmes to address internal constraints to empowerment.