Stellar mass distributions of merging and non-merging galaxies. Top: Original samples, which are similar in shape but statistically different (AD and KS tests). Bottom: Ratio-matched control sample, where non-mergers are randomly down-sampled in stellar-mass bins to reproduce the merger mass distribution without enforcing equal sample sizes. The result corresponds to one realisation from 1000 Monte Carlo re-samplings. Controlling for stellar mass does not change the conclusions.