Personality isn’t accidental. You deliberately decide which personality your community will have.
Helpful and nice is great, but boring. You shouldn’t decide on this personality by default. 4Chan isn’t helpful or nice. But they’re successful. Fiercely competitive is rough, but productive. Sarcastic is addictive, but tiresome. 'Know-it-all’ is vocal, but don’t expect much to happen.
You cultivate the personality of your community with every decision you make. This includes which members you invite, what content you encourage, which contributions you recognise, what events you run. These are all personality decisions. Decisions you need to get right or your community is doomed.
You can’t change the personality of your audience. All you can do (all you should do) is be sure the personality of your community precisely matches the audience. Right down to the wording. This sounds easier than it is. It takes just one misplaced smiley to destroy all your work.
