Rejection Therapy [1] is what I would think a perfect example of antifragility in the wild. [2] People learn to manage their anxiety in stressful social situations and become more resilient to rejection after playing for awhile. Entrepreneurs like Jia Jiang even leverage rejections to launch and grow their startups. [3]

[1] http://rejectiontherapy.com

[2] http://www.theglobeandmail.com/life/health-and-fitness/healt...

[3] http://www.entresting.com/blog/100-days-of-rejection-therapy...