The development of new ideas and more knowledge is the biggest growth accelator, for society and individuals alike. 

>> I’m not convinced this is correct. I think the incentives of the systems within which we operate are possibly more important than knowledge in terms of growth accelerants.

Therefore, please tell me, if your objective was economic growth, should you rather spend time with and talk to someone who was totally different from you, or with someone who was almost identical to you?

>> It depends. If the other person is ‘too different’ I may not be able to comprehend his outlook. The energy lost to the cognitive dissonance (when encountering someone wildly different) may detract from understanding the alternative views/methodologies on offer.