Most parents know when their children are telling fibs.
Children show their emotions on their faces and in their actions, think tantrums. Unlike adults, who learn to hide their feelings. A shame really — we tend to get that stiff upper lip as we age, keeping our emotions under wraps.
Perhaps if we didn't do that as much and expressed how we felt more often there wouldn't be so many people trying to cope with anxiety and depression.
What you are doing also has a lot to do with mood and facial expression. For instance if i go to see my grandchildren and they are outside playing they always greet me with much enthusiasm, loud voices, hugs and smiles,
However, if I happen upon them inside with eyes down, a device clutched close to their body, I'm lucky to get a hello as their eyes dart to me and back down again.
It's the same scenario with adults. If you meet them when they are at the beach on a beautiful sunny day or relaxing with friends, there are smiles all round.
However, meet the same person in the middle of a day when everything has gone wrong from the moment they stepped out of bed and things are very different.
Generally though we Kiwis are happy to smile at complete strangers. When I'm out walking I always smile and say hello to people I meet. Most of them respond in the same way.
Unlike the Russians who are known for their grimaces rather than their grins. Apparently in some countries smiling is not a sign of warmth or respect. No, it actually evidence that you are a tricky fool.
That made me wonder why we aren't allowed to smile for passport photos.
Was it because customs officers are all sombre people and don't like looking at smiling faces day in and day out?
Was it because it makes everyone look like fools?
No, there is actually a reason for it according to Mr Google.
Apparently a passport has a chip in it containing biometric information about you, derived from the photo you supplied when you applied for the document. That image is scanned, and key relationships unique to you about you (distance between the eyes, tip of the nose to the chin) are used to generate a mathematical map.
Anything that distorts or disguises those measurements – such as a wide smile – reduces the effectiveness of the algorithms used.
So while smiling is good most of the time — sometimes it's just not the done thing.