In this experiment 20 horses were handled according to a defined schedule in order to assess the effects of social environment and training on the human-animal relationship. 8 horses were housed singly and 12 horses were housed in 4 groups 3 horses. Horses were handled three times per week in 10 min sessions from an age of 6 months until 2 years of age during two winter periods. The training scheme involved leading, tying up, touching, lifting feet, etc. in 43 stages. The horses had to fulfil the performance criteria of each stage in order to get to the next stage. In the first winter period, horses were led to the stable when they had ‘passed’ a stage or after 10 min of training. In the second winter period, horses would start off at stage 1 again, and when they ‘passed’ a stage they went on to the next stage within the same training session. There was a significant difference between trainers in the number of times they allowed a horse to ‘pass’ a stage within each winter period. Group housed horses ‘passed’ more stages than single housed horses and singly housed horses bit the trainer more frequently than did group housed horses. From the responses of group housed horses to training, from this experiment it was apparent that there are clear benefits of raising young horses in groups.