It would be safe to state that, although Equus caballus clearly have innate patterns of behaviour, the feral horses being studied today have many adaptive consequences imposed by occupying new niches in geographical locations for which they have not evolved.
Horses evolved to ultimately live in groups in large open spaces, like plains and savannahs, but have adapted fairly well to life in places so marginal as the desert of Namib, or the coasts of Assateague and Chiconteague. Clearly the behaviours observed from these feral horses have many points in common, thus the commonality of the species, but again surely their behaviour must also differ in consonance with the constraints inevitably imposed by their relatively new environments.
A clear example of this, is that many feral horses no longer suffer selective pressures from predatory animals like larger canines or felines. This lack of predation, even if only to the slightest degree, must necessarily affect group cohesion, but not only in horses as it must be so for many other prey species as well.
A comparative approach between feral horse populations is hence called for, if any macro-determination of the behaviour of Equus caballus is to be sought. This means not that the observations on feral horses up to date have been futile, but it does mean that to have a fuller picture of equine behaviour, one should consider a “broader spectrum”, one which would invariably include particular adaptations to particular environments.
This would entail the consideration of a range of behaviours similar or differing across the species depending on the selective pressures of their environments. The existence of scarce resources or that of over-abundance will surely vary their life strategies. It would surely be naive to consider that a well fed animal would behave (goes about his/her business) in the same manner as one that is hungry.