I had a bit of an epiphany last night - we were talking to DSS about choices - he's really struggling with the responsibility of growing older (he's yr 5) and often displays helpless behaviour or sheer panic when given responsibility for simple personal tasks.
Anyhow, in the course of conversation he revealed that he doesn't have any choices at his mums. We explained that he may not realise it but he had choices every day - whether to get out of bed, whether to get dressed etc etc - and that he chooses to do those things because the consequence of not doing them is something he doesn't want to happen.
It became apparent that he has been taught obedience. He does what he is told by his mum purely because she tells him to. He doesn't display the same obedience to school teachers or activity leaders - and often ignores directions from them, but he really struggles with taking the initiative and coming to a decision for himself as to what to do.
When he was younger, it made for a very compliant child - but now he's older and is expected to walk to school alone, take responsibility for his own belongings etc, it's more of a concern as he freezes and becomes helpless when he faces a situation that he has not received prior instruction/warning about!