The p-value is a statistical term used in medical research to suggests whether a result might be statistically significant or not. But despite the p-value being an "objective" measure of statistical probability, it has introduced a new concern in research, namely p-hacking. P-hacking is a type of bias where researchers collect or select data until nonsignificant results become significant. It also happens when researchers try a multitude of statistical analyses and cherry-pick those with significant results. Researchers do this because there is a strong incentive to publish significant results, since evidence suggests that journals prefer to publish significant results over non-significant ones. Chapter 2 is thus concerned with how p-hacking and other types of statistical hacking can negatively affect medical science.