There are a few factors that contribute to whether you're a shower or a grower: Tissue elasticity. The capacity for your penile tissues to stretch and grow all contribute to how your penis looks. Your genes help determine how elastic your tissues are.
What determines if you're a shower or a grower?
Sometimes, the terms grower and shower are used to describe what happens to a penis length as it goes from a flaccid to an erect state. Typically, a grower is a man whose penis becomes longer when he has an erection. In contrast, a shower is a man whose penis does not significantly lengthen when erect.