Skinner is now credited as the father of operant conditioning: a form of learning where a subject is conditioned to respond to a secondary reinforcer through association with some form of primary reinforcement. Not only did Skinner's work show that associations between primary and secondary reinforcers appear in nature, it also demonstrated that new reinforcers can be manufactured.

Skinner and Pavlov proved that primary reinforcers are extremely powerful motivators. After sex and sleep, bacon is one of nature's most powerful primary reinforcers, partly due to its high fat and protein content in comparison to other meats. Bacon has become known as the "gateway meat": the smell triggers intense cravings, even in vegetarians. But in our modern world, our instinctual craving for bacon and other fatty foods can cause significant health problems.

The box also taught us two fundamental lessons, one of which had ramifications that extended far beyond Skinner's experiments. Humans are hardwired to respond to primary reinforcers, just like any other animals. And while primary reinforcers have a diminishing effect once we're satiated, secondary reinforcers, like money or social status, exist outside our biological needs, and these never hit a satiation point. In other words, we are hardwired to seek approval from our peers, and we can never get enough of it.

Many people defend FarmVille as a harmless distraction, arguing that the thousands of hours spent playing the game would still have been wasted on other activities. But there's no question that the social game market, with its virtual currencies and unlimited stock of goods, is a huge cash cow. And it's also clear, when you look more closely at FarmVille, that it was engineered with one goal in mind: to coerce users into tending their virtual plots of land for as long as possible. Using our natural tendency to reciprocate gratitude from our peers, we end up pestering our friends to keep returning. And cleverly-timed crop cycles force players to return to their farms at all times of day. But what about the techniques employed in other games?

Black, White, and 254 Shades of Gray

Moral relativism aside, I think "bad" games exist -- provided we define "bad" in unambiguous terms. In Groundwork of the Metaphysics of Morals, Immanuel Kant tried to specifically define this with the Categorical Imperative: a set of rules that could gauge an action's morality. But regardless of how we choose to evaluate a game's morality, there are certain traits which can push it closer to the "evil" side of the spectrum.

The primary characteristic of unethical games is that they are manipulative, misleading, or both. From a user-experience standpoint, these games display dark patterns, which I define as common design decisions that trick users into doing something against their will. Dark patterns are usually employed to maximize some metric of success, such as email signups, checkouts, or upgrades; they generally test well when they're released to users.