Nature...

[Shining_Stealth]

Whats with the nature thing? I mean, I'm adamant, and some others are lonely, etc...

 

[IceX]

I think you can change your nature if you want to

 

[Zone]

You change it as a part of your profile.

 

[Chairman Kaga]

The various natures visible in members' postbits are based on the Nature feature in the Pokémon Ruby/Sapphire/Emerald and Fire Red/Leaf Green games. To change yours, go to User CP, click on Profile, and there will be a drop-down box with various natures to choose from.

Edit: Threads like this tend to generate a lot of cookie-cutter replies, so I feel it's best off closed.

 

[Lily]

'Natures' is a fun add-on, originated from Ruby/Sapphire and such. It's up to the user to decide which one they prefer, and changing/using it is entirely up to your own free will.