Depends completely on the chinnie. They are never as affectionate as a cat or dog, but can get really tame. Sammy is my sweetie. He loves to be held and petted, he'll fall asleep in your arms. Ellie won't approach me, If I want her, I have to reach in her box and get her (which I only do when weighing her) She was raised on breeding farms for the first 5 - 8 years of her life with almost no human interaction. She's not used to this "pet" thing. Lexi I got when she was a baby, and she was never one to be held, at all! She'll play with me, run over to me, climb on my hands, but I can't hold her or restrict her in any way or she freaks. Gus was 8 or 9 months when I got him almost 2 months ago. He's a little like Lexi, but more willing to jump in your arms and be carried around the room, he's super curious about everything. Paisley and Sylvester are both about the same, very shy, but sweet, they like to be held, but aren't going to jump into your arms like Gus. Buddy (daddy to these babies), doesn't care to be picked up or held much, but is more willing than Ellie (came from the exact situation as her). And Bailey, mom to these babies, came from the same situation as Buddy and Ellie, but she's a total sweetie! As soon as the cage door opens, she's leaning out for kisses. She loves being a spoiled pet. Such a sweetie!
None of them ever bite, some chins do, but I can't imagine what you'd have to do to them to make them mean! They are naturally just non-biters.