1) Social impact assessments evaluate the effects of planned interventions and major projects on people and communities. They emerged in the 1960s to address social issues not covered by environmental impact assessments. 2) Social impacts refer to changes in people's well-being and ways of living, both positive and negative, experienced differently by various groups. Vulnerable groups are often most severely affected. 3) Social impact assessments identify affected groups, facilitate stakeholder participation, predict impacts, and recommend mitigation measures to minimize harm and maximize benefits for all parties.