I haven't followed the link as I know it would upset me.
I don't think cruelty is learned from computer games though, I think it is a big problem which has been several generations in the making with a society which is increasingly selfish and values material things above living things..... and parents who don't have empathy themselves so what hope is their that their children will have.
Having said that, I don't fuly understand as I don't recall my mother 'teaching' empathy, it just seemed to be a natural thing. I naturally even as a small child did not want to hurt or harm someone or thing - and always respected animals and found wonder in them, loved watching them and appreciated them as creatures that feel.
There are strong links between animal cruelty and abuse against people - so anyone who thinks this isn't an important issue "because it is only an animal" needs to consider "if we tolerate this, what next?".
Although I know it perhaps isn't very empathetic of me, I could quite happily agree with physical punishment similar to the crimes committed against the people who conduct animal cruelty for 'fun'.