I have known a lot of cats over the years and those weaned too early always had some type of emotional or adjustment problems. The cats who were with their moms until mom said it was "time" were all well adjusted, creative, happy, loving cats. I'm dead set against voluntarily separating kittens from their mothers before eight weeks and prefer 12 to 14 weeks. The kittens will have a lot happier lives the longer they stay with mom.