If you mean identically? No, you should be the same. Your personality is a combination of genetic and chemical expression. If that is identical, to what you had a second before, your personality should be the same.

So when you're whole body looks different (different face, shape of body, length) you keep the same personality?

I think yes, to a certain extent, your personality will certain change. When I say change, however, I mean evolve/adapt, not completely overhaul your personality or give you a new one.

One simple example of this is aging. While Philosophim makes a good point that many of our traits are electro/chemical, these often act/react and change to external stimuli. When you are younger, you are often bolder and more daring compared to old age, though of course this is not necessarily the case with everyone or to the same extent. And yes, this is definitely impacted by your brains electro/chemical state which does change with old age, but, even someone who feels young inside will often feel their age when they see themselves in the mirror. Their physical appearance undoubtedly affects their personality, which is how they interact with the world and even their own 'Minds eye' so to speak.

Another example of this can be seen in people born with one biological sex but identify as another. Many will choose to transition physically in order to look how they feel, fuelled in part by the fact that their personality is being impacted by the discomfort and potential insecurity caused by not seeing who they would like in the mirror. This is obviously a gross oversimplification, I don't mean to offend anyone who is going through or has gone through this by claiming to know exactly how they feel.

Hi!

An interesting question. My first stop was to check on human cell longevity. If brain cells had a short enough life span, the question would be moot. As luck would have it, they can last our entire lifetime.

The next thought was that our 'self', including personality, is defined by interactions between brain cells, and not by the cells themselves. Changing a cell may not be of consequence if it does not change how the cell interacts with others.

I at least got this far.

Regards to all.

So when you're whole body looks different (different face, shape of body, length) you keep the same personality? — CarpeDiem

Oh, in that case, your personality would likely change a little. Imagine being short, then suddenly becoming tall. Or being tall, and suddenly becoming short. As a male, your interactions with other people would likely change significantly. This goes from being beautiful, to being ugly as well.

I would put though that your personality would likely change with other people, but your private personality might remain the same.