I would only use 'behaviour' (AE 'behavior') in the singular.
How so? Acting up may include more than one behavior right?
"Control his behaviours" sounds sinisterly Orwellian.
The Longman dictionary says "behaviour" is uncountable, see http://www.ldoceonline.com/dictionary/behaviourHow so? Acting up may include more than one behavior right?
It's strange that they should get something like that so wrong.The Longman dictionary says "behaviour" is uncountable, see http://www.ldoceonline.com/dictionary/behaviour
It could be about a dog, a robot, or any number of things that exhibit behaviour. There's nothing to indicate parents, except that they are one example of people who have some control over the behaviour of something that can be referred to as 'he'.I interpret the sentence as a parental declaration.