Have you hit your unhappiest age yet?

>> but first this is "today" on nbc.

>>> this morning on "today's five facts," the truth about happiness . good morning.

>> good morning.

>> how do you even define happiness ? is that one of the five things.

>> a large question.

>> state of being , a mood, a mood state really, and we can't be in it all the time, but people do try to optimize how often they can feel happy.

>> it's not just about genes or family upbringing.

>> that's right. that only accounts for hamp of your happiness which is really important because people often feel like they are a born a happy person or they are or their life experience can make them happy or not, but you can control happiness . it's how strategic you are with your coping mechanisms that can determine a lot of being able to be happy which is great because biology is not your destiny.

>> second fact is interesting though about how we handle our body and minds. the connection to all of it.

>> and exercise is huge. so exercising up to 20 minutes three times a week can boost your happiness 10% to 20% which is big. actually exercise goes head-to-head with anti-depressants from mild to moderate depression so really doing something aerobic physical makes a huge difference.

>> is it how our bodies are producing?

>> there is, there's a relationship between activity and reducing stress level.

>> number three jumped off the page at me. has to do with the age because my wife is 37 years old.

>> should i be worried.

>> not if she's not unhappy, but peak age does tend to be and unhappiness and for men it's 42. it's really that mid-life you have a lot of pressures. made a lot of your choices already, picked your spouse and not picking another one, picked your job and kids are young often at that time and they are not necessarily a source of happiness , even though they are a source of joy, but -- but older, you have more perspective and that actually helps with happiness .

>> so the notion that you're happiest in your 20s is not the case.

>> not the case.

>> people would believe, no responsibility, carefree.

>> mid-life is the harder time and later on there's a lot of happiness , later in life.

>> this one has to do, is that right, smell?

>> why are you looking at me.

>> do you smell happy?

>> let me smell you.

>> you might.

>> you smell pretty good.

>> smell like the pumpkin pie i was making with katie lee .

>> well, stress changes your body chemistry and happiness does. release different hormones when you're happy and it has a scent which is pretty interesting, but most importantly, i think of these facts, is the fact that performing random acts of kindness will actually boost your happiness . five random acts of kindness , just writing something kind to a stranger, doing a favor for somebody, five of those a week will raise your happiness level for up to three months.

>> and you don't think of it really in the course of your day, but when you do it, it's so true.

>> can be small things.

>> and it really does. it boosts your own mood.

>> thank you. that's something good.