I mean it’s missing. “We are our brains + long range signalling molecule emitting organs” is better but it doesn’t roll off your tongue does it?

I am hangry when I’m hungry which means my stomach is a part of my personality (my responses to stimuli), not just my brain. Disregarding endocrine system is not scientifically honest.

Cancer (unwanted tissue) can change your personality (cancer is at the wrong place and actually changing brain signals or simply due to constant pain) and we remove them. Likewise, removing unwanted gonads can improve someone’s well-being (it was causing constant misery = personality change).