And now for something completely different...

Feedback loops in social-ecological systems, illustrated by Loopy (a fairly positive optimistic chap who likes to strengthen those around him by giving feed back to them) and Loop (quite a negative pessimistic bloke who wants to get an equal share of feed back after giving it away). 

It makes sense, really... 

Negative feedback loops keep things in balance, whereas positive feedback loops tend to escalate. Therefore I conclude that, based on this logical deduction: 

Optimism is a bad thing