Like all other organisms, the human mating strategy is part and parcel of our overall survival strategy. In our case, we are extreme “K-specialists,” i.e., we devote a huge amount of investment and resources in our offspring, compared to, say, willows who just scatter their seed to the wind by the millions.
Human females have also developed a strategy of concealed ovulation. The current scientific consensus is that by concealing her ovulation and maintaining a perpetual state of potential sexual readiness, the human female makes it difficult for males to know whether her offspring are theirs. The male counter-strategy is to be at hand as often as possible to prevent cuckoldry. Together, this strategy and counter-strategy promote pair-bonding, monogamy, and dual parental investment, thus maximizing parental investment in offspring.