Bill Gates tends to focus on issues like poverty and infectious diseases through his foundation, but there is a problem with the politics of the United States.

He admitted in the keynote conversation at this year's Forbes 400 Summit on Philanthropy that political polarization may bring it all to an end. I don't know anything about that. I wouldn't know how to spend my money.

The spread of misinformation is one of the issues that goes hand in hand with political polarization.

He said that the lack of trust is a problem. Robert Kennedy said in his book that he likes to make money and kill people with vaccines. That sells well.

Gates and his ex- wife have given billions to vaccine research, development and delivery. Conspiracy theorists say that Gates puts chips in vaccines to track people. Gates said people yelled at him on the street.

The truth is boring sometimes. Gates told Forbes that anyone with good innovations on reducing polarization, getting the truth to be as interesting as the crazy stuff, would be a good investment.

"Why We're Polarized" is one of the books on Gates' summer reading list.

"I'm generally optimistic about the future, but one thing that dampers my outlook a bit is the increasing polarization in America, especially when it comes to politics," Gates wrote.

Gates told Forbes that he and his ex-wife hope to keep the foundation going for 25 more years to focus on infectious diseases.