In the TED talk, a woman named Laura Rover went over solitary confinement and what it does to people. Solitary confinement is placing a person in a small room without seeing anyone for almost their entire day. This technique of punishment is used in many countries, usually in secret because of how inhumane it is, and the damage it does to people mentally.
There is a facility that operates in Colorado where this is done routinely every day. Inmates have to spend 23 hours inside a bathroom-sized cell, and this is extremely destructive to the brain. Humans are social creatures, and not seeing another for so long can hurt us. People went crazy, and for good reason.
The US is telling lots of countries like a grand prophet that solitary confinement is inhumane, and that they should not use it, while we are using it ourselves. It is way too effective, like poison gas. Banned from WW1, using poison gas was considered a war crime, because it caused widespread suffering and pain. Solitary confinement should be dropped from use in all nations, as no person would ever deserve it.