What to watch for in tonight's Leaders Debate.

It will be interesting tonight because unlike the last debates back in 2010 we now have seven leaders to watch not just the three big party's.

For me one of the most interesting to watch will be Nicola Sturgeon.

Why?

Because unlike the men she doesn't use her hands an awful lot, very rarely in fact. She doesn't feel the need to show power and dominance through her hand movements, instead she uses lots of facial expressions, smiles, eyebrow raising, head nods and tilts.

So what else is there to monitor as our illustrious leaders speak and debate with each other?

As I just mentioned above with Nicola Sturgeon, the hands will play a key role in how effective and how passionate they each are on any given topic.

Power movements like fist clenching, banging down on their lectern.

Finger wagging and pointing at each other, we might also see some beating down gestures as though they are using an imaginary implement to to beat the other leader down.

Incomplete movements, these are when they don't quite finish a gesture. An example would be the index finger and thumb meeting, like they are using a precision instrument.

However, sometimes the finger and thumb don't quite meet, which could mean they are not quite complete intheir thinking on that particular point or policy.

Smiles, you'll see lots of them I'm sure but not all will be genuine and it is very hard to fake a genuine smile. Simple reason is the Zygomatic muscle at the corner of the mouth doesn't work if the smile is forced. It doesn't pull the corners of the mouth up to meet the corners of the eyes.

Also, genuine smiles take time to fade from the face whereas fake smiles disappear in an instant, Gordon Brown was particularly bad at doing awful, instant smiles for the cameras.

Nodding and shaking of the head is pretty obviously a "Yes" or a "No" so look for them when other leaders are talking do the others agree or disagree? They often let slip that they agree or disagree with another leader without saying a word.

Drinking water, licking or biting lips shows they are feeling the tension so take note of how often each of them dinks, bites or licks.

Sweating is another giveaway that someone is feeling the pressure. It's fine if all the leaders look pretty sweaty then it's probably extremely hot in the studio with all the lights, heat from cameras and the audience.

But if only one or two are sweating, why?

And lastly Micro Expressions.

These falsh across the face in less than one quarter of a second but you can spot them if you look. The most common you'll see are Contempt, where the lip curl upward on one side like a small snarl.

Fear, as a member of the audience asks a question, then fear expression is immediately replaced by a smile that they think you want to see.

Disgust is quite an easy one to spot as the nose wrinkles up or to one side, like someone has just stuck somethin unpleasant under their hooter.

Here's a little piece I did for the Press Association on the leaders body language in the upcoming debate

Leader's Debate Video