There are those who say that love is the key to understanding, but if scientific understanding is meant, I do not think they are right. It would, however, be even more unscientific to regard hatred as the key to understanding. Every emotion, whether friendly or unfriendly, distorts judgement.
Source: "As others see us" [From: Mortals and Others: Bertrand Russell's American Essays, 1931-1935, v.1 (1975)]
More info.: https://russell-j.com/AS-O-SEE.HTM