Penis size is relative to IQ

Josh scrolled through the seemingly endless stream of rules with astonishment. All the answers to life were here at his fingertips; no more soul searching or meditation on a mountain peak!

...But was it real? Was it all true? A simple test needed to be conducted to verify its authenticity. His fingers slowed the scroll speed until one rule about the human body caught his eye. He made one quick change to this rule:

"Humans have tails."

As he hit save, he felt an odd sensation emanating from his tailbone. A mix of burning and tingling washed over his midsection, not quite painful, but something was definitely happening!

Once the feeling subsided, he turned his head to see a tail through a hole in his pants swishing back and forth! ...Unfortunately, he was nondescript, so this new protrusion looked in many ways like an arm, all fleshy and covered in short hairs. Kinda gross, but a bit expected, actually. Looking around, everyone passing by also has a tail much the same as his! Women has smoother tails, but maybe they shave them in addition to their legs?

Anyway, this was a test run, and it worked! The app really let's you alter the rules to reality! Now to have some REAL fun!

Josh quickly deleted the rule about tails, immediately feeling a shrinking sort of sensation as his tail disappeared. Another success! Thought long and hard about his next rule. Long and hard... right! Eureka! With a proud sense of purpose, Josh swiftly typed the new rule:

"Penis and testicle size is relative to IQ."

Wait. One minor correction:

"Human penis and testicle size is relative to IQ. The higher the IQ, the bigger the penis and testicles, and vice versa."

Whew! That could have been very... awkward in the animal kingdom, assuming this affected non-humans. He pressed "Save" and waited for the effect.