Living with my two cats is an ongoing lesson in genetics and psychology and the idea of nature vs. nurture.  The cats are brother and sister from the same littler, adopted at the same time, and raised the same way.  But the differences are striking: 
  1. Dilbert (the boy) bites and scratches people.  Nemo (the girl) is known as "the nice one".
  2. Dilbert eats his toy mice after he plays with them (cloth, plastic, and all).  Nemo plays for a few minutes and gets bored.
  3. Dilbert eats anything and everything.  Nemo sniffs it and walks away.
  4. Dilbert sometimes sits up at night to eat the bugs that come crawling out from under the stove (we have a seasonal cricket problem).  Nemo plays with the bugs for a few minutes and gets bored.
  5. Dilbert sometimes walks around the house at night meowing.  Nemo goes to bed early.
  6. Dilbert attacks Nemo.  Nemo screams and cries.
  7. Dilbert chases neighborhood cats to either (a) kill them or (b) mate with them.  Nemo runs away.
If they came from different parents, I could understand.  If they were raised in entirely different environments, I could understand.  The only real difference is that Dilbert is male and Nemo is female.  (Dilbert had a leg injury when he was younger, and the vet visits, shots, and force-fed medicine might have something to do with his behavior, but I contend he was vicious before all this.)  They're both neutered/fixed.  They're both well-fed.  They're both showed love and affection.  So why the huge differences?  I guess the answer is genetics. #science