Editor’s Note: Washington Week with The Atlantic is a partnership between NewsHour Productions, WETA, and The Atlantic airing every Friday on PBS stations nationwide. Check your local listings or watch full episodes here. House GOP infighting reached new heights this week as Trump-aligned House Republicans threatened to shut down the government.

This is an edition of The Atlantic Daily, a newsletter that guides you through the biggest stories of the day, helps you discover new ideas, and recommends the best in culture. Sign up for it here.For those of us who have siblings, these relationships will likely be the longest of our life. That fact is a basic statistical one, but it’s also an emotional one.

This article was originally published by Knowable Magazine.We’ve all heard of the five tastes our tongues can detect: sweet, sour, bitter, savory-umami, and salty. But the real number is actually six, because we have two separate salt-taste systems. One of them detects the attractive, relatively low levels of salt that make potato chips taste delicious. The other registers high levels of salt—enough to make overly salted food taste offensive.

Once upon a time, presidential impeachment was a rare event. But with four of the five inquiries in U.S. history coming in the past 25 years, people seeking to understand and explain the impeachment inquiry into President Joe Biden, launched Tuesday, have looked to the 2019 impeachment of President Donald Trump as an analogy. Both center on allegations of using elected office for personal gain, and both have been divided sharply along partisan lines.

Ever since Elon Musk’s lackeys began fiddling with the algorithms of X (formerly Twitter), I have noticed a distinct shift in the content that is pushed onto users. My “For you” tab is now a nest of tradwives, shoplifting videos, and that guy who has strong opinions on trouser creases. It is also home to the kind of old-fashioned misogyny that I once thought was on the decline.