The finding that people tend to be most attracted to others whose liking for them appears to have increased, and least attracted to others whose liking for them appears to have decreased, such increases and decreases in the perceived estimation of others having more impact on their attraction towards those others than constant levels of liking or rewarding behaviour from them. The phenomenon was first remarked on by the Dutch philosopher Baruch Spinoza (1632–77) in his Ethics, published posthumously in 1677: ‘Hatred which is completely vanquished by love passes into love; and love is thereupon greater than if hatred had not preceded it. For he who begins to love a thing, which he had wont to hate or regard with pain, from the very fact of loving feels pleasure’ (proposition 44). The phenomenon was first studied empirically by the US psychologists Elliot Aronson (born 1932) and Darwyn E. Linder (born 1939) who reported in the Journal of Experimental Social Psychology in 1965 the results of an experiment in which students overheard conversations in which they were being discussed by a fellow student either entirely positively, entirely negatively, beginning with negative comments and becoming more positive (gain), or beginning with positive comments and becoming more negative (loss). The students were later asked how much they liked the fellow student whose conversation they had overheard, and the results showed that their liking was greatest in the gain condition and least in the loss condition.