Pasture-kept horses have the ability to interact socially and are exposed to a rich environment, but have less contact with humans than their stall-kept counterparts. A 1997 study* has found that in spite of decreased human intervention, young pasture horses might be easier to train than those kept in stalls. In the Michigan State University study, 16 2-year-old Arabian horses were started in training: half were kept in pasture during the study, the other half were stalled.
* Behavioral And Physiological Responses Of Horses To Initial Training: The Comparison Between Pasture Versus Stalled Horses, E. Rivera; S. Benjamin; A. Morrison; L. Callender; B.D. Nielsen; A.J. Zanella