For example, I have doubted claims that the Pythagorean theorem was proved independently. I have many posts doubting that Einstein re-discovered relativity independently.
Here is an example from psychology:
In one of the uncanny synchronicities of science, autism was first recognized on two continents nearly simultaneously. In 1943, a child psychiatrist named Leo Kanner published a monograph outlining a curious set of behaviors he noticed in 11 children at the Johns Hopkins Hospital in Baltimore. A year later, a pediatrician in Vienna named Hans Asperger, who had never seen Kanner's work, published a paper describing four children who shared many of the same traits. Both Kanner and Asperger gave the condition the same name: autism — from the Greek word for self, autòs — because the children in their care seemed to withdraw into iron-walled universes of their own.The article makes a good case that both of them stole the idea from Georg Frankl. He directly worked many years for both of them. See also History of Asperger syndrome.
A NY Times book review does not know about the connection:
The history of science is studded with stories of simultaneous discovery, in which two imaginative souls (or more!) turn out to have been digging tunnels to the same unspoiled destination. The most fabled example is calculus, developed independently in two different countries by Isaac Newton and Gottfried Wilhelm von Leibniz, but the list stretches back centuries and unfurls right into the present. One can add to it sunspots, evolution, platinum, chloroform ... and now autism, as the science journalist Steve Silberman informs us, identified separately by Leo Kanner and Hans Asperger. The crucial difference is that Kanner had the fortune to publish his work in Baltimore, while Asperger had the misfortune to publish his in Nazi-controlled Vienna, and this accident of geopolitics lies at the tragic core of Silberman’s ambitious, meticulous and largehearted (if occasionally long-winded) history, “NeuroTribes: The Legacy of Autism and the Future of Neurodiversity.”No, autism was not independently identified by Kanner and Asperger, and maybe I should doubt some of those other stories. It is my understanding that Newton and Leibniz were not as independent as it appeared, as they saw unpublished manuscripts from each other. I guess some people say that Darwin and Wallace independently discovered evolution by natural selection, but I am not convinced that any of that was independent. I don't know about sunspots, platinum, and chloroform.