This chart compares the observed height differences between husbands and wives in U.S. heterosexual couples from 1999 to 2023 with the distribution that would be expected if people paired randomly regardless of height. The horizontal axis shows the difference in height between partners in inches, with negative values indicating the wife is taller and positive values indicating the husband is taller. The pale red bars represent the expected distribution under random pairing, while the black outline shows the actual distribution observed in the data. The comparison reveals that couples in which the woman is taller than the man occur significantly less often than chance alone would predict, while pairings where the man is moderately taller are more common than expected. Very large height differences are also slightly less frequent than a random model would suggest. The findings indicate that partner selection is not random with respect to height and that there is a strong preference, whether conscious or unconscious, for relationships in which the man is taller than the woman. This pattern is consistent with previous research on assortative mating, showing that social preferences and dating behaviour influence partner choice beyond what would be expected from the height distribution of the population alone.