When cross-examining, it’s the heart rate stupid…

5 May 2022
London International Disputes Week
When cross-examining, it’s the heart rate stupid…

As cross-examiners we often start our questions tortoise like, slow and steady, looking to get the witness to agree with us on the small stuff, so they get into a pattern of agreeing with the questioner: it is hard to say no to someone when you have been agreeing with them a lot.

We are also fond of using building blocks, slowly working our way to the inevitable rhetorical flourish, of “you did it didn’t you”. And then of course there is the golden rule that you must never tell a witness they are lying in the first few questions.

I must confess that has largely been how I have cross-examined over the last twenty-two years. It has also been how most of my opponents have done it too. It seemed pretty effective, and I have always thought do it well: “if it ain’t broke why fix it”.

But what if is broke and we cannot see it.

Over the last few months watching Assurety’s performance psychologists in action with witnesses using cutting edge heart rate monitoring technology, I have begun to seriously question whether this well-trodden method is not only ineffective, but also counterproductive. What if we barristers, in being so focused on getting our questions right, are failing to take advantage of what is actually going on in the head of the witness?

If we stopped for a moment, we would realise that all witnesses (including the masters of the universe) when they start giving evidence will be in a state of anxiety and tension. Their heart rate will be spiking, their breathing shallow, their palms sweaty. They are tense, dry mouthed and struggling to concentrate or focus. They may be tired, having been up all night worrying about the next day. In other words, their body and mind is reacting to intense pressure.

Looking at the readings from the heart rate monitor on a screen behind an Assurety witness during their practice cross-examination I have come to realise how important heart rate is to witness performance.

The heart is a key organ for sending messages to the brain, in fact some scientists say it is the heart that controls the brain, rather than the other way around. When the heart rate is chaotic, it is telling the brain to be in flight, fright or flee mode. It is causing the brain to prioritise the physical over the cognitive part of the brain. When the heart rate is calm and constant, (achieved primarily through effective breathing), the thinking part of the brain takes over. It is obvious which of these two heart rates is the best for the witnesses. Conversely it is obvious which heart rate the questioner should be seeking to get the witness in.

Without fail, whenever the questioning starts, the heart rate variability during the practice cross-examination is chaotic and scrambled. The questioner needs to keep it there for as long as possible and the cross-examination should track the contours of a chaotic heart rate. This is achieved by putting the witness on the back foot straight away; by asking leftfield (but relevant questions) to unsettle; by avoiding chronological questions; by even calling a witness a liar in the first few questions. It should avoid doing anything that allows the witness to get their eye in and calm their heart rate down: basically, it’s the exact opposite of what most of us, including me have been doing for decades.

“it’s the heart rate stupid”…

Ed Williams QC

Director of Assurety

The only top ranked provider of witness familiarisation, Chambers and Partners 2020 & 2021