Minimizing the screen by clicking on the title bar?

[Imola Ghost]

I'm not sure how I have it set but on my 13" MBP I can click on the title bar and the screen will minimize however on my 27" iMac I don't have it set this way.

Can someone tell me how to set this up on the iMac? I know it's just a setting but it seems quite hidden, at least to me.

 

[simsaladimbamba]

System Preferences > Appearance >> Double-click a window's titlebar to minimise.

 

[Imola Ghost]

Thank you, easy enough!