Genetic differences do exist among different human populations. Even so, attributing broad behavioral traits to Neanderthal ancestry is not supported by science.
Human behavior is shaped by many factors like genetics, culture, environment, and social structures. No credible geneticist argues that Neanderthal ancestry “explains large portions of variances in human behavior.”
As for your comment that “Biologists know this, you won’t catch them saying it in public though.”, this is a classic conspiracy-style statement. You’re suggesting that experts are hiding the “truth,” which is a tactic often used in pseudoscience and race-related theories.