The New York Times has an important article about how animal cruelty is being increasingly recognised as part of a wider pattern of behaviour including anti-social violence and criminality.
Cruelty to animals has been implicitly recognised as being a sign of behavioural problems in children for some time as it forms part of the diagnosis of conduct disorder, characterised somewhat glibly as ‘kiddie psychopathy’.
However, research has been slowly accumulating over the last few years that animal cruelty is related to lower levels of general empathy and is a signal that the person concerned may have abusive tendencies that extend towards other people.
The link between animal abuse and interpersonal violence is becoming so well established that many U.S. communities now cross-train social-service and animal-control agencies in how to recognize signs of animal abuse as possible indicators of other abusive behaviors. In Illinois and several other states, new laws mandate that veterinarians notify the police if their suspicions are aroused by the condition of the animals they treat. The state of California recently added Humane Society and animal-control officers to the list of professionals bound by law to report suspected child abuse and is now considering a bill in the State Legislature that would list animal abusers on the same type of online registry as sex offenders and arsonists.
The article is an extensive investigation into the cross-over between criminal psychology and forensic veterinary science and, although disturbing in places, is an important and in-depth look at how the two types of abusive behaviour share common roots.
Link to NYT on ‘The Animal-Cruelty Syndrome’.
Mind Hacks 
Training people like animals is what happens in the psych ward of a hospital, but this training is judged “good” for the patient. The patient isn’t a prisoner of course, they can leave any time they like.
But how about recognising that all exploitation of other species is cruel behaviour, since,
a) it always involves violence, and –
b) by definition it involves overriding the interests of other sentient beings: i.e., it inevitably and intrinsically demonstrates lack of empathy.
See: http://www.plosone.org/article/info:doi/10.1371/journal.pone.0010847
“lower levels of general empathy” are thus displayed by anyone who avails him- or her-self of ANY of the products of other-species exploitation, not just by perpetrators of egregious examples of abuse.
What definition of sentience are you using?