Necromancy lies in the dye of the beholder

People also tend to be ticklish in those areas

My theory would be because the neck is your literal lifeline to your body. It's a very fragile structure and the only thing keeping your brain supplied with blood and oxygen.
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An exposed throat can be slashed, crushed, snapped. It leaves you extremely vulnerable, and is why people and animals tend to try and protect their necks.
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It's also not an area that gets a lot of foot-traffic. Your feet, hands, arms, legs, back, butt, etc all get stimulation or are in contact with things throughout the day. The neck far less so.
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Following this logic, it only makes sense your body would be on high alert whenever anything goes near your neck.
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But, again, that's just my thought

Yeah, not entirely wrong, but there are, or can be erogenous zones in the areas you mentioned too

Eh? Oh I wasn't going against the theory of an erogenous one. My theory would be part of why the area is an erogenous zone

Ah, I didn't pick that up, but yes, that could definitely be a part of why it's sensitive, could also be a part of why the sides are sensitive too, but what about the less vulnerable parts, like arm pits?

I mean, the armpits fall into the "barely any foot traffic" category generally. Or mine do at any rate.
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They're also fairly close to the lungs and heart, and if I remember right contain some very vital arteries and nerve bundles that can lead to death quite easily. So in their own way they kind of fit into the first category as well

Fair point, my arm pits see a bit more "foot traffic" I suppose, and that's likely why people have different erogenous zones I think

What you and the pigeons get up to is strictly your business. I ain't here to judge

Inner thighs, with the very vulnerable femoral arteries so close to the surface, would seem to support your theory.