Chow chows have a bad reputation because they can be aggressive. Their powerful hunting instincts mean they can sometimes regard cats and small dogs as prey (unless they know them).
Chow chows are fiercely independent and stubborn – in fact, they’re sometimes described as ‘cat-like’. They’re very aloof and you can’t force them to do anything unless they want to.
So, they have a reputation as being hard to train. While a puppy can be properly socialized and trained, modifying the behavior of an aggressive adult chow chow can be very difficult, even for a professional.
For these reasons, chow chows are not generally recommended for families with children. While they are protective towards their families, they’re really not that playful and may react badly to being harassed or treated roughly.