Knowing human nature, both intrinsic and extrinsic motivation exists. Money is merely one extrinsic motivation among many, which turns out to instead undermine our intrinsic motivation according to the meta-analysis of various studies. We would be committing both oversimplification fallacy and false dilemma fallacy, if we simplify both intrinsic and extrinsic motivation into merely consisting of monetary motivation.
"The results indicate that the association between salary and job satisfaction is very weak. The reported correlation (r = .14) indicates that there is less than 2% overlap between pay and job satisfaction levels. Furthermore, the correlation between pay and pay satisfaction was only marginally higher (r = .22 or 4.8% overlap), indicating that people’s satisfaction with their salary is mostly independent of their actual salary.
In addition, a cross-cultural comparison revealed that the relationship of pay with both job and pay satisfaction is pretty much the same everywhere (for example, there are no significant differences between the U.S., India, Australia, Britain, and Taiwan)."
"The first is a classic meta-analysis by Edward Deci and colleagues. The authors synthesized the results from 128 controlled experiments. The results highlighted consistent negative effects of incentives — from marshmallows to dollars — on intrinsic motivation. These effects were particularly strong when the tasks were interesting or enjoyable rather than boring or meaningless."
"Intrinsic motivation is also a stronger predictor of job performance than extrinsic motivation — so it is feasible to expect higher financial rewards to inhibit not only intrinsic motivation, but also job performance. The more people focus on their salaries, the less they will focus on satisfying their intellectual curiosity, learning new skills, or having fun, and those are the very things that make people perform best.
The fact that there is little evidence to show that money motivates us, and a great deal of evidence to suggest that it actually demotivates us, supports the idea that that there may be hidden costs associated with rewards. Of course, that doesn’t mean that we should work for free. We all need to pay our bills and provide for our families — but once these basic needs are covered the psychological benefits of money are questionable. In a widely cited paper, Daniel Kahneman and Angus Deaton reported that, in the U.S., emotional well-being levels increase with salary levels up to a salary of $75,000 — but that they plateau afterwards. Or, as Arnold Schwarzenegger once stated: “Money doesn’t make you happy. I now have $50 million but I was just as happy when I had $48 million.”"
"Finally, other research shows that employees’ personalities are much better predictors of engagement than their salaries. The most compelling study in this area is a large meta-analytic review of 25,000 participants, where personality determined 40% of the variability in ratings of job satisfaction. The more emotionally stable, extraverted, agreeable or conscientious people are, the more they tend to like their jobs (irrespective of their salaries). But the personality of employees’ is not the most important determinant of their engagement levels. In fact, the biggest organizational cause of disengagement is incompetent leadership. Thus, as a manager, it’s your personality that will have a significant impact on whether your employees are engaged at work, or not."