Functioning should be more valued than intelligence! I have an "IQ" of 140, was in gifted classes, and yet struggled with most adulting tasks all my life. It took a long time for me to grasp how to manage money (in my 40s), and when it comes to social interactions I still have to work hard to be appropriate. I have a dx of autism and ADHD - but unlike your brother, I had nice parents and a secret weapon - my sense of humor. My problem is being socially slow and verbally quick. IQ tests are extremely unhelpful - I'd say punishing - for people like me. The expectation was I'd do great things, and aside from my ability to write (and play Scrabble and word games), I don't have many practical talents. It's a frustrating way to live but unlike your brother, I didn't grow up with a lot of trauma. I can't imagine trying to deal with this sense of relentless failure and chronic disappointment without having the psychic fortitude provided by a safe, loving home and without the intellect to gain insight. Being this way has throttled my self-esteem. Thankfully, getting diagnosed with ADHD and autism is helping because I'm finally allowed a realistic picture of myself.