If you would like to watch the full video of the reading, sketch and talk that created this blog, (it was live streamed on our Church’s Facebook page, as we do with all our Sunday evening talks) you can find it here

If you would rather listen to it, you can via the link below at the end of the blog.

Possibly the best book I’ve read in years (except for the Bible of course), is “Mistakes Were Made (but not by me)” (Carol Tavris & Elliot Aronson – Pinter & Martin, London 2015). It’s a very insightful, entertaining and thought-provoking book on the science of psychology behind cognitive dissonance and self-justification. It doesn’t sound interesting I know, but brilliantly written with great illustrations from real life on almost every page.

Anyway… within the volume they have a section on our propensity to self-justify our actions, especially our wrong ones, in ways that can become destructive. They explain Stanley Milgram’s experiment from the 1960’s.

In essence, Milgram asked volunteers to take part in an exercise to see if a small electrical shock administered after incorrect answers to questions could improve the recipient of the shocks ability to learn. In reality, he was wanting to find out, post WWII, about those who justified their atrocious actions by the excuse they were “just following orders”. Were they evil, or more worryingly, were they just like you and me if we were pressed by someone with seeming authority? If so, how much pressure would be needed?

Unlike the voltage scale above, Milgram’s electrical shock machine was graduated with 30 switches from 15 volts (Slight Shock) to 450v (Danger: Severe Shock XXX). When the subject answered a question incorrectly, the voltage applied was increased incrementally. If the person actually being studied (the one administering the shocks) started to pause or doubt, the Experimenter only gave up to four verbal ‘prods’ to proceed:

  1. “Please continue”
  2. “The experiment requires you to continue”
  3. “It is absolutely essential that you continue”
  4. “You have no other choice but to continue”

The volunteers were only paid $4.50 to take part.

At what voltage do you think people stopped and said enough is enough. 30v? 60v? 100v?

Milgram repeated his experiment in 18 different versions and got broadly the same results. Two thirds (65%) pressed the switch that they thought connected the learner to… 450v. 100% went as far as 300v.

Tavris and Aronson point out that this is the result for those who agreed to take part. For those asked directly how far they go in would administering a shock to someone, almost no-one said they would go to 450

What was happening here?

Well, a 15v shock isn’t much is it. You could do the experiment and give the same shock to the volunteer first and they would agree – no problem in doing that for science. But what when it was 25v? Not much of an increase, and it’s for science – the shout of pain is just a slight one. “By the time people were administering what they believed were strong shocks, most found it difficult to justify a decision to quit” (MWM pg 49)

When our actions don’t match our belief system we suffer from cognitive dissonance – we’re psychologically uncomfortable and we need to restore mental comfort. We either change our behaviour back in line, or we self-justify why our action is OK and shift our belief system just a notch.

In Milgram’s experiment we see this writ large. At each incremental step, volunteers move from it’s a “fun shock for science” almost to a “this guys so dumb he deserves the shock!” 450v can very easily kill someone, 65% thought they were administering that. In the UK our voltage is limited to 240v and people die from electric shocks every year – and 100% of the volunteers who joined in went on to press the 300v switch.


In the Bible, chapter 3 of the ‘Letter to the Hebrews’ uses this phrase – “don’t harden your hearts”. At the opening of this chapter there is a plea to “think carefully about this Jesus” – the “this” referring to the explanation in Chapters 1 & 2 of who He is, the fully Human, fully God who helps in times of testing and is the route to a full life now – and after death.

This ‘hardening of hearts’ is something we all need to be wary of. In all walks of life we can start to slip. For example, finding a new friend. We get to know them and like them more. Then they do something that frustrates us a bit. Now we don’t like them as much, but our cognitive dissonance doesn’t like that feeling. We need to justify why we feel that way. Then we like them less… here is where it can all go wrong if we don’t understand our mind at times such as these.

One option is to just forgive the person – it was nothing after all, and we all have foibles.

An alternative option is to think worse of them – that it’s a character flaw – in them. Next time they do something a little annoying, we will have a tendency to ramp up our negative feeling towards them, and now we’re on a slippery slope. Not only is this action they’ve taken annoying, but our cognitive dissonance kicks in again and they just make us feel even worse – they are now ‘actually’ hurting us. When someone hurts us, our reaction becomes more severe. It doesn’t really take that long for a BFF (Best friend forever) to become an enemy.

By this stage we’ve ‘hardened our heart’ towards this person we started out liking.

We can apply the same principle to life and the creator of that life, God himself.

The slippery slope of negative feelings creates dissonance that hurts, and it can then generate yet more self-justification and reduction of behaviour or belief to an even lower base level than before. It seems to be a flaw in our psychology. (I’ll leave that to others to explore whether it could be the theological explanation of our DNA from when original sin came into the world – but it’s not a bad starting point to think about.)

How do we break the cycle that leads to a hardened heart? If we find our belief and behaviour is slipping from a norm that we just know to be correct, that we believe but now don’t adhere to, what might we do?

Hebrews Chapter 3 gives one answer: “Think carefully about this Jesus”.

Many years ago I produced this graphic to try and explain cognitive dissonance and its similarity to our conscience.

It’s a balance scale with the Bible in the middle. If our actions and beliefs are both right next to God’s instruction for a full life, its in balance. But if our actions move away from the middle, we’re unbalanced – or psychologically we’re uncomfortable as we’re suffering from cognitive dissonance. Our actions now aren’t matching our beliefs and the balance shifts from horizontal.

We can only resolve our discomfort one of two ways. The first is to re-adjust our actions, back to the middle and level back up – or alternatively modify our belief to match our action, by moving a little way from the scripture that could be our standard, but again levelling up and becoming comfortable again.

As we have seen, the slippery slope of self-justification and continual discomfort of repeated dissonance will just keep moving us away, both our actions and our beliefs, from our norms – eventually to a point where there is no longer a standard to which we hold ourselves, other than… ourselves.

And herein lies a difficulty so many of us have with scripture. We start out not believing it – no one approaches the Bible on day one trusting it, that would be odd. Over time, as we spend time with it we discover its truths, its coherence, its trustworthiness. Then the world starts to suggest alternative behaviour. Maybe stealing a pen from work – “well its not stealing is it, we have thousands of them”. But it can then move to modifying expenses a little “well, I put in extra hours I’m not paid for…”. Each time we shift down the slippery slope. The move can get broken by a sudden realisation that this is just wrong, and we move back up the slope – or we get caught – or we just keep on self-justifying and allow ourselves to slip further down the slope. But how far down that slope might we go if we truly harden ourselves, if we smother our conscience?

If we don’t have an ‘absolute’ standard, we don’t have a fixed norm and our behaviour and actions will constantly be in a battle. What Milgram’s experiment showed is we all have the ability to act in ways we can’t imagine we ever would. It is not about people being ‘evil’, rather it’s about people not saying ‘no’ when they know they should and justifying worse and worse behaviour until eventually – you can’t self-measure any more.

If the Bible says, “think carefully about this Jesus” as a way to avoid a hardened heart, maybe a good starting point might just be to explore who Jesus really is. If the conclusion is that he was on earth 2000 years ago (and most historians don’t disagree with that), its then maybe who he said he was. He self-affirmed he was God’s Son, that if you wanted to know what the Father was like, you needed to look at Jesus etc etc.

So, was Jesus an outright liar, fully knowing he wasn’t God? In which case why didn’t he defend himself and avoid the Cross? Maybe he was insane? But many take his moral teaching as a fantastic example, as others have said, ” they are the sort of words we might expect God to say”. Or, could he have been the person many wrote about and died for? Could he really be a liar or seriously mentally ill… or might he just be who he said he was?

If we want a firm fixed point so we can assess how we’re doing, how we can overcome our psychology that could lead us into very real difficulty, a place where our hearts are hardened so much we may do something we’ll really regret, maybe, just maybe, the advice from Hebrews to “think carefully about this Jesus” could be a good thing to do.

Talk only: "Psychology And Hardened Hearts" St Jude's Church, Plymouth 22 April 2018