This fascinating anecdote describes an extremely subtle and effective form of psychological manipulation and behavioral conditioning allegedly employed by French wives in the Middle Ages.

The Flawless Strategy:

Assigning Blame: Wives cleverly linked the physical discomfort (headaches, nausea, depression) caused by the mild poison to the husband’s behavior of being away from home. The slow-acting nature of the compound perfectly set up this false attribution.
Reinforcing the Belief: The worsening symptoms the farther a man traveled solidified a false belief: Leaving home was physically harming him. This is a textbook example of powerful negative conditioning.
Love as the Cure: Upon his return, the wife administered the “antidote.” The immediate and dramatic relief it provided powerfully reinforced the opposite connection: The wife and the home were the sole source of healing, comfort, and safety.
The men were thus tricked into believing their misery was caused by the negative magic of absence, rather than a controlled chemical compound. The result? Husbands became deeply and voluntarily attached to their homes and wives, avoiding late-night escapades.

The tale is a stunning, albeit dark, illustration of how applied psychology can be used to maintain social order and domestic stability, even when disguised as a simple daily ritual.