I'll go first.
The first time I realized I was racist was in the summer of 1998. Ironically, my best friend at the time was Marshall Gaskin, a big, black, beautiful man: a gentle giant and an incredible artist. We lived in adjacent buildings in an artist’s co-op just outside of Toronto. I’m grateful for having known him, for he was a major influence in my life. Sadly, he is no longer with us.
One day at the co-op, I was going through the underground parking lot and came across a young black man leaning on a car door towards a young white woman seated on the other side of the open window. Without hesitation, I pointedly looked at the woman and asked,” Are you alright”? She nodded, and I walked away.
My stomach turns at the memory of it. Who the fuck was I to presume that this woman was in trouble. The same feeling I had the next day, upon realizing what I had implied to a complete stranger.
More and more, I became acutely aware of my racism. Like the time I was in an elevator with three black men much larger than me. I noticed that I felt uncomfortable, and my heart started to pound. Faster. Faster. I thought, “What the fuck. This is racism! If these were three white guys, I would be cracking jokes.” After leaving the elevator I was grateful that I could see through the bullshit. I’ve extracted and examined most of my racist moments, and although I think I will always be racist to some minor degree, I acknowledge that any is too much.
I write this because I recently recounted a story that my mother told me to a group of friends. It was a story that my uncle would often repeat about a souvenir tin plate from Niagara Falls. I realize now that this wasn’t a story about something my uncle purchased. It was a racial slur wrapped in a story that he could tell over and over again. I never liked that he enjoyed making fun of minorities, and yet here I was … participating.
I write this because I am sorry.
I write this because I’m ashamed.
I write this for Marshall.
I miss you buddy.

He technically is only talking about correlation, not causation. He's also technically not blaming it on their race.
It's often found that black-majority neighbourhoods in the US do worse on IQ tests. But that's due to a lack of investment in education in those areas as a result of systemic racism, not because of a racial "disability". There's a correlation but no causation.
And it's no secret some people do slightly better or worse in some areas. It's obviously not true that any biological differences end at the skin colour. Just look at the overrepresentation of east Africans in endurance running for example. The important part however is that those differences are just that: differences. It doesn't make anyone a better person that anyone else.