Hitting head

This has become a little stressful recently. Bernice is still hitting her head and she has been doing so for the past 4 months or even longer.

At first, we were not too worried and attributed it to:
1) trying to gain attention
2) angry or upset and she learnt the art of beating from Daddy, who will hit her hand when she does something wrong

Now, her head hitting is getting quite bad, as she will hit her head when she is not angry or upset even, and she is not trying to gain attention. As observed yesterday, when we are just carrying her or when she is just quiet, she can suddenly hit her head.

Yesterday night, just before she fall asleep, she was hitting her head quite a few times while lying down.

Now, this is gettting a little worrying, coz she hits her head quite hard. And, we have tried a few ways of getting her to stop but its not getting better.

Just hopes its not because she learnt this from Daddy, or because she is feeling insecure, or because .....