[Ria P]

I think that you are overthinking this.

Clive's still throwing himself about scent marking when he's out and i approach him with the intention of picking him up. Even when i start talking to him he responds physically by scent marking and jumping about.
Never saw this as anything neurological though and more as a behavioural response he may not even be able to control.
Like very shy people blushing when someone talks to them. Or a young child hiding behind the mother when someone talks to them.

I thought Clive would have outgrown this by now but it's almost like he's confident one day and back to the beginning the next. It doesn't take much to unnerve him either.

I think some hamsters aren't as robust mentally as others, naturally or affected by their past.

I also believe that everything will fall into place with time, acceptance and patience.