There are plenty of movies that have used a transplanted organ as a plot device – a transplanted hand that turns the survivor into a slasher, a transplanted heart that makes the person gentler. (Heck, look at the Tin Man in the Wizard of Oz).

I doubt it is provable in a scientific way, because the person who LOST the organ (heart, hand, not kidney) is likely to be dead, and therefore there is not a control in the scientific sense.

Conceptually, it’s hard to see how an arm or a leg or a heart can convey personality traits, but anything’s possible.

I think there’s a possibility ‘muscle memory’ might translate in some way.

Few of us do the exact same things the exact same way, every time we do that action.
Say you get a hand transplant.
When you were 2-handed you always drove with your hands in the 10 an 2 position. Well, nearly always, as there’s fatigue to relieve, etc. First you break the cycle by losing a hand. Then you receive a transplant from someone who’s dominant driving style was right (transplanted) hand at 12. Since that was one of your fatigue relievers when you were 10/2, you fall back on 12, and it just feels right. Physically, the hand is geared to 12 o’clock driving, muscularly and to an extent, even skeletally.

I also think that we’re more in tune with our internal organs’ “happiness” than we’re conscious of. If you were a fairly inactive person and received the heart of a health nut, your heart might reward you with a sense of contentment if you feed it some endorphins.

So, no, basically I don’t think organ and personality traits are linked. But I can see how an organ could influence the physical traits of a new owner, and come out as ‘personality’.

This reminds me of the “Eye” story in the John Carpenter Film Body Bags

It’s called cellular memory and there have been quite a few cases documented.
Some even say that cultural cellular memory exists.

The change in interests probably comes the anti-rejection medicine, rather than the actual organ.

People think of the brain as being where all our consciousness is, but the nervous system runs all through the body, is connected and made of the same stuff. Furthermore, our emotions and history seem to be spread about our body.