Reintroduction of an endangered species or subspecies is only the first step towards ensuring survival and population increase. The first phase of takhi (Equus ferus przewalskii) reintroductions has been successful, but populations remain at risk from isolation, resource competition with humans and livestock, and hybridisation with modern domestic horses. Greater social cohesion in takhi family groups reduces the risk of individual and group isolation and of hybridisation, which in turn increases the integrity and vigour of reintroduced populations. The aim of this study was to investigate potential behavioural mechanisms of social cohesion in reintroduced takhi, exploring mechanisms of cohesion both within and between family groups. Interindividual spatial distribution served as a surrogate measure of cohesion, and potential mechanisms included interindividual interactions and differences in individual reproductive state, personality, and group membership. Social network analysis was used to identify classes of takhi significantly central to spatial and interaction networks. Two repeatable personality traits were detected (sociability and assertiveness), but reproductive state had a stronger influence on cohesion than did personality. Mares were the most active managers of intragroup spatial distribution. Stallions were the most active managers of intergroup cohesion. Stallions and colts were most active in intergroup affiliative networks. Overall, reproductive state most clearly dictated individual involvement in interactions influencing intra- and intergroup cohesion, while group membership and personality influenced intergroup spatial cohesion. This study is the first to incorporate personality assessment and fine-scale spatial data into an investigation of Type I equid social structure in naturally established, free-living takhi family groups. Future takhi management efforts should focus on monitoring interstallion relationships, colt social development, and filly dispersal as the primary sources of variation and changes in group and herd level cohesion in takhi populations. Results of this study can be applied to adaptive management of takhi populations, and groups and herds of other Type I equids, including feral and domestic horses