Toddler who wont feed himself??

Hi Guys!
I have a question regarding my 16 month old. He is very fit and healthy, but refuses to feed himself!! If I break things up for him into pieces, like toast or biscuits etc, he will feed himself, so I know he can do it, but will not feed himself things unless he can fit it all in his mouth! Most of the time, I am still putting things in his mouth. If I do give him a whole biscuit, he will either try to shove the whole thing in his mouth or just sit there with half of it hanging out before it just drops to the ground. Im not sure if this is just the sort of thing that he will do in his own time, or if by now he should be quite able to do it. Is it something to do with his motor skills? Everything else about him is perfect, I find he is very intelligent. Any advice? Have any of you experienced this?

My eldest was quite happy for us to feed him most of the time until he was 18months old. He could feed himself finger food but he would grabs handfuls and try to put it all in sometimes. I don't think there is an issue with him, he just needs to practise it a bit more I think.