"The present acts as a magnifying effect for our emotions," Hershfield says - which means a desire right in front of us feels more powerful than a long-term one and can pull us away from that goal.
This is even more true at work, where "we're not fully in control of the things we do," he says. If the boss sets priorities that are different from yours, "that gets in the way of whatever your goal is."
Still that doesn't mean there aren't ways to better manage the forces at work that derail us.
We asked Hershfield and two other experts on goal-setting and decision-making to explain the science behind how we can boost our chances of staying on track with those professional promises we make to ourselves.
1. Make it public.
At holiday dinner tables and New Year's Eve parties, we've all been asked the same question: Making any resolutions this year? We often answer with personal goals to lose weight or spend less - somehow replying "getting a raise" or "getting promoted" seem a little less appropriate.
But research has shown that making resolutions public can be one of the best ways to follow through on them, says Drew Carton, an assistant professor at Wharton who has done research on goal-setting.
"It's much harder to flout promises - even promises you make to yourself - when others know that you've made them," he writes. "We don't like the ignominy that comes with other people knowing that we haven't met our goals." While we may not want to share some goals with everyone, finding a few trusted friends or colleagues to tell our goals to can make us more successful than keeping them private.
2. Set milestone markers.
A challenging professional goal can seem particularly daunting on its own. But breaking it into smaller pieces can make reaching it less overwhelming.
"There is usually a bit of a motivational let-down just after you reach each subgoal, but this is more than offset by the motivational uptick that happens just before," he writes.
But setting such milestones also depends on what kind of goal you have.
Carton points to research by On Amir and Dan Ariely that shows that when the distance to a goal is unclear - you don't know exactly what it will take to reach the ambiguous goal of getting promoted, say - "discrete progress makers," or indicators of how you're doing, can help reduce uncertainty and improve performance. However, that research also found that if the distance to the goal is clear - deleting all 5,000 emails in your inbox, say, or paying down a mortgage - such progress markers can shift motivation away from the end goal and actually decrease motivation.
3. Use 'if/then' statements to form new habits.
Part of what makes following through on New Year's resolutions so tough is that it's hard to always monitor our behavior, Carton writes; changing our habits instead is more effective.
One of the best ways to do this, research has shown, is to use "implementation intention," or an "if/then" strategy. Putting our work goals into these kinds of statements can make us stick to them better. For instance, if you're trying to not check email during the more productive morning hours, then you might tell yourself "if it's before 11 a.m., then I won't check email."
Hershfield said it can be particularly helpful to use the calendar to do this.
Instead of just abstractly saying you want to get more organized, the calendar can become a practical way of implementing those "if/then" plans ("If it's between 9 and 10 a.m., I'm going to clean off my desk and go through that stack of old reports.") "The basic idea there is it's going to be a lot easier to follow through with our goals if we give ourselves a plan," Hershfield said.
4. Don't think too positively.
We often hear about the "power of positive thinking" and are urged to stay positive and not get discouraged when it comes to reaching our goals. But this time-worn wisdom isn't enough, and can sometimes even backfire.
Gabriele Oettingen, a professor at NYU and author of the book "Rethinking Positive Thinking," said in an interview that too much optimism about a goal gets in the way of the energy needed to reach it.
"What happens is that people feel accomplished," she said. "It's accompanied by a kind of relaxation. Blood pressure goes down, energy goes down, and we do need the energy to accomplish these wishes." Oettingen's research has shown, for instance, that the more positively university students fantasized about their smooth transition into work life, the fewer job applications they sent out and the fewer job offers they received.
But that doesn't mean people shouldn't fantasize about reaching their goals, Oettingen said. The trick is to combine it with a recognition of the obstacles that stand in their way, a strategy she refers to as "mental contrasting." "That's what people usually forget, because people have been told to think that thinking negatively is all bad," she said. "It's imagining the future, but then also what actually hinders you and what is it within me that stops me from fulfilling my wish. It's a rational strategy, an imagery strategy."
Oettingen's research has shown that the mental contrasting idea, combined with the "if/then" strategies described above, are so effective they've created a method and corresponding app to help people and students with goal-setting.
5. Look for other fresh starts.
If the goals you set at New Year's don't pan out, try setting them again at another obvious milestone.
Research has shown that other natural breaking points - such as starting a new job, or even just the start of a new week, month or financial quarter - can also be effective for motivating us to make progress on our goals quickly.
"We use these periods as opportunities to 'disassociate' from the 'old me,' " Carton said. "When we think about our personal or professional lives, we don't think of ourselves as maturing at a constant rate over time. We think of our development as a set of chapters, where each chapter has a distinct narrative and a distinct feel."
