How people perceive spiciness depends on the person.
What one person thinks is spicy another person might not.
この場合、次のような言い方ができますよ。
ーHow people perceive spiciness depends on the person.
「辛さの感じ方は人それぞれである」
to perceive で「感じる・理解する」
ーWhat one person thinks is spicy another person might not.
「辛いと思うのは人それぞれ違う」
例:
A: Did you think the food was spicy at that restaurant?
「あのレストランの料理辛かった?」
B: How people perceive spiciness depends on the person. I didn't think it was so spicy.
「辛さの感じ方は人それぞれだけど、私にはそんな辛くなかったよ」
ご参考まで!