Whether you want some simple applause for a project that turned out well or a promotion worth thousands of dollars per year, the quest for accomplishment at work seemingly is never-ending. But what precisely drives us to take up our laptops one more time, to log more hours when we're already exhausted? What are the rewards we really want?

1. Inclusion

When we accomplish something, accolades from our boss or teammates confirm that we are on the "right" path, meet the approval of others, are capable or skilled and worthy of being in the larger group. Subsequently, we're less afraid of being isolated.

2. Security

From an evolutionary perspective, more is associated with survival. Score lots of food for example, and you can get big and fat and get through the winter. We are designed in this way to seek more. Work accomplishments might not help us out physically--one certainly can argue that a stressful job has negative health implications. But mentally, having accomplishments pile up makes us feel like we've got a good store to fall back on and as though we have earned the right or "enough" to feel safe. Probably the best example of this is tenure. Accomplish x years of service, for instance, and you don't have to worry about losing your job.

3. Power

Even though we're usually too polite to verbalize it outright, reaching a work goal gives us an opportunity to turn to the Joe/Jane Schmoe next to us and subliminally say, "I did it, you didn't, I'm bigger and better." The accomplishment thus becomes comparative, enabling us to communicate that, at least for the moment, we're in a solid position of dominance.

4. A sense of identity

You probably don't need a newsflash to understand that reaching goals at work strokes your ego. Each time you accomplish something, you're able to tell yourself "I can!", defining yourself as capable. But accomplishment often connects to other elements you probably connect to your identity, too. For example, the education you draw on to achieve, the experience you have of acquiring and applying that knowledge, is also part of your identity. Work accomplishments thus both confirm and round out who we are.

5. Usefulness

"Why am I here?" is one of the most basic philosophical questions we ask ourselves. We constantly are looking for meaning, and we find that meaning in feeling useful. The problem is, we look at time in a rather messed up way. We quantify it based on our salary or hourly wage. And as we do better in a good economy, we start to see our time as more and more scarce, because valuable things typically are rare. We prioritize work and deny ourselves the chance to rest or do other things. Subsequently, some of the only opportunities to feel like we have been useful to others come from our jobs. We might not have the time to teach the neighbor's kid Spanish, for example, but we can file, cover a shift or prop the company up with a good investor pitch. With those accomplishments, at least, we feel we've helped, and that we matter.

Why you need to care

As a leader, understanding what really motivates people for one more pat on the back is essential because it affects how you present the work you want done. If you're not able to offer tasks in ways that help people feel included, secure, powerful, self-confident or useful, workers aren't going to be happy and they'll likely eventually leave. This is particularly critical for small business leaders, who have a harder time recovering from or accommodating the loss of even a single employee.

At the same time, introspectively, understanding these motivators also helps you identify how your own work could be more rewarding, or why you are drawn to specific jobs over others. But perhaps most importantly, it can help you draw boundaries. Recognizing you're only taking on projects because you otherwise feel meaningless, for instance, can inspire you to look for ways to make a difference outside of work with friends, family members or people in your community.

The bottom line? You probably don't need another trophy. Face that. It's OK. Connect with the deeper desires you have and be honest. That's the first step in truly powerful change.