The Partridge Family made it popular to shake a tambourine and sing, “Come on, get happy.” Scientists aren’t completely in rhythm with the sentiment – they’ve found that 50 percent of happiness is determined by our genes. Chalk up another 10 percent to life circumstance. But that still leaves 40 percent we control daily.

Even better news? Ninety percent of long-term happiness stems from how your brain processes the world, not the external world itself. But that doesn’t mean you can’t use things to your advantage. So we know that gratitude, exercise and spending time with loved ones are on the to-do list. But here are a dozen immediate, concrete, scientific ways to stimulate for happiness:

1. Hit your pillow. Yep, shut-eye is important for happiness. That’s because sleep deprivation shuts down the hippocampus section of the brain, which processes positive memories. And while you can’t remember the good times, the amygdala is working just fine, processing negative stimuli.

2. Smile with your eyes. Take a moment for a positive thought. Notice how your eyes narrow from the smile? That genuine expression improves attention and helps you perform better on cognitive tasks.

3. Reach for the yellow crayon. Yep, it’s the optimism color. The next time you’re in the dumps, add a splash of yellow to your outfit or the walls.

4. Get your om on, too. Yoga may be more effective at boosting mood than other methods of exercise, not to mention improving immunity.

5. Go outside. Just 20 minutes in the sun helps our bodies produce vitamin D, the depression antidote. The American Meteorological Society also reports that happiness is maximized at 57 degrees (13.9 Celsius).

6. Smell the flowers every morning. Looking at flowers first thing in the morning leads to increased happiness and energy and decreased anxiety.

7. Plan a trip. You don’t even have to take it. Studies show the highest happiness spike happens in the planning stage, and the boost lasts for eight weeks. (Not a traveler? Thoughts of watching your favorite movie raise endorphin levels by 27 percent.)

8. Stop driving yourself. AKA choose a short commute over other job benefits. Two Swiss economists found that possessions cannot make up for the misery a long drive creates.

9. Give away 100 hours a year. Yes, this step comes with a timer, which boils down to two hours a week (with two weeks off for good behavior), devoted to helping others.

10. Go to bed angry. Contrary to popular opinion, anger catharsis is overrated. Expressing anger over irritations just amplifies the bad feelings. Zipping your lip often allows it to dissipate.

11. Have meaningful conversations. Scrap the small talk — people who discuss deep concepts and emotions are also the happiest.

12. Have birthdays. Growing older makes you naturally happier. Maybe it’s because as people age, they seek out situations that will lift their mood. Or perhaps it’s because older adults learn to let go of loss and disappointments and focus on their well-being.