I gotta disagree. We kept our little one close, never used a sitter, used the church nursery maybe twice. She’s almost always with one of us. And yet she is utterly trusting, never met a stranger, wanders off all the time, that kind of thing. Sure this is anecdotal, but it does belie what the article is saying.
I’m with you. We kept ours close, he is an only, I stayed at home. Hardly ever had babysitters, except for my sister (and she had 6 kids to our “only”, so it was more like another home to him.) We moved out of the country for a couple years when he was young, and in that whole time, we never had a babysitter. Then I homeschooled.
As to the “kid”...never met a stranger, talks to everybody, always came away from a strange setting, even visits to many foreign countries where he couldn’t speak the language, and he would have made “friends” along the way.
He’s grown now, but the “outgoing” nature has served him well in college, grad school, and his jobs.
P.S. He does have a sense of adventure, which I think he inherited from my husband. They’re always doing physical things that to me have an edge of danger like white water, rock climbing, scuba diving, etc. I, on the other hand, don’t even like roller coasters, LOL.