Thinking Allowed

The Believability Formula
by Jon Thompson

This month, I’d like to put forth an unusual idea. It’s one that might seem bizarre at first. The idea is simply to calculate a rough approximation of what your audience expects your persona to be using a mathematical formula.

I said it might seem bizarre, and it’s okay to scoff at such a notion. I hope, however, that by the end of this instalment of Thinking Allowed I’ll have changed your mind. Either that or made you curious to know more.

Before I introduce the formula, I’d like to explain that it came about as a result of reading acres of print on the subject of creating a believable performance persona. The formula is an attempt to show what, given your age, experience, and a few other factors, you might expect an audience to believe is the origin of your abilities, and why it may be futile to make assertions to the contrary.

The formula attempts to answer some of the circular arguments people have about age and mentalism. Is a 40-year-old with 2 years experience ever going convince an audience he’s the real deal over a 20-year-old with 5 years under his belt, for instance? Or would he be better off working on patter to do with a more scientific approach?

Knowing what the audience expects as the origins of your ability could give you a head start in figuring out and fine tuning what your performing persona can be – as opposed to what you’d like it to be.

If any reader wants a free spreadsheet of the formula to play around with, find bugs in or generally laugh at, by the way, please don’t hesitate to contact me through the email address at the bottom of this page.

Below is the formula in full:

X = E/A
B = S – ((S-X)*T)

I’ve put the calculation of X in its own step because this is a rather useful value in itself.

E is the number of years since you became aware of a natural ability, or since you began learning the skill you’re demonstrating.

A is your age in years.

X is a calculated value and represents what the audience accept as being the origin of your ability. It’s calculated by dividing the number of years you’ve had the ability (or been practicing a deliberately learned skill) divided by your age, and is expressed as a decimal number between 0 and 1. A low value indicates that the audience would be prepared to accept that your ability is natural in origin. A high value indicates that it’s expected that your ability is something you’ve learned.

S is what you state as being the nature of your ability, again expressed as a decimal between 0 and 1. If you say it’s something scientific you’ve deliberately learned, studied and worked at, the value of S should be close to 1, whereas if you’re claiming some form of natural ability, it should be closer to zero. Somewhere about 0.5 would be half and half, indicating that it’s something you’re naturally good at or have an intuitive feel for, and which you’ve deliberately developed into the performance the audience sees before them.

T is the number of distinct and apparent abilities on display during your performance.

B is the variable we want to calculate. The lower this value, the more natural your ability can be portrayed to the audience. The higher it is, the more of a trickster you will appear regardless. If you set the variable S to something at odds with this value, such as claiming to be the real thing when B is very high, you’re less likely to be believed than if you’re stating something close to B.

Okay, let’s crunch some numbers.

Suppose we have a 20-year-old who’s been honing a single ability for 5 years. X (the expected origin of his talent) comes out as 0.75, meaning that the audience is likely to expect that it’s a 75% learned ability backed by a natural aptitude.

Let’s also suppose that our young mentalist states that he’s about to demonstrate something he’s definitely learned, backed with a small natural ability in what he’s doing. In saying so, he gives S a value of about 0.75.

Given these values, B also comes out at 0.75. In other words, the audience’s expectation is in line with what the young mentalist says he’s doing and what his effects could be perceived as (as denoted by X). In other words, it’s expected that he’ll be demonstrating a predominantly artificial ability he’s spent half his teenage years honing. What these high values of X and B also indicate is that how he portrays his ability is going to have to be something along scientific lines to be in keeping with the audience’s expectations.

However, our 20-year-old decides he wants to come across as the real thing. He claims that his ability is entirely natural. He gives S a rather low value of 0.1. His problem is that B still works out to 0.75.

Clearly, this is at odds with X. But if he claims this ability first became apparent 15 years ago rather than 5, when he was still a small boy in fact, the formula shows that the audience is far more likely to believe him, as reflected in a new value for B of 0.25. This makes sense: if such a thing exists at all, natural psychic ability traditionally tends to develop in childhood.

According to the formula, our young mentalist is on the right track for appearing to posses a natural ability by increasing the number of years he says he’s had the talent. However, he’s also keen to expand his range of apparent abilities, but how many people who believably claim they’re the real thing also claim to have multiple abilities? Not many. Here’s possibly why it’s a bad idea to do so.

Leaving all other variables the same, and simply increasing the number of abilities on show to 2 increases B from 0.25 to 0.4. If he increases the number of abilities on show to 5, the value of B rockets to 0.85. Given his age and experience, the more abilities on display, the less believable he is as the genuine article. So, to come across as having a real, natural ability, the young mentalist is going to have to limit himself to the ability he says he was born with. This makes perfect sense, and the formula holds.

Let’s create a further test with a second example: This time the mentalist is 40. He’s been performing for 20 years. He does a one-man thought reading act, which he pitches as a natural talent he’s nurtured and honed. Let’s say he sets the value of S at around 0.6 by saying that he has a natural talent for second guessing people that he’s developed over two decades. In this case, B comes out at 0.5, meaning that the audience expect what they see to be about 50/50 between nature and nurture. This means he’s actually pitching the natural side of his ability slightly modestly.

What happens if our 40-year-old suddenly tells an audience that he’s only been reading thoughts for just 5 years, leaving all other variables as they were? B now shoots up to 0.88, meaning that the audience will expect that the talent on display to be almost entirely a learned ability due to the time he’s been at it. He’ll need to switch to a more scientific explanation for his act (thereby giving S a high value) if he’s not to be at odds with the audience after claiming shorter experience.

He decides instead that he doesn’t want to come across as some sort of boffin, and so goes back to being a 40-year-old with 20 years experience. He states that his abilities are half and half nature and nurture (S=0.5), but he decides to add more abilities to his act. Now he has 5 abilities on display. Oddly, B is still 0.5, as it was before he dropped his experience to just 5 years. Why is this?

If our mentalist claims an equal mix of nature and nurture, he can add extra abilities to his act and it will do little to B provided he claims to have been doing what he does for a long time. There’s a kind of equilibrium at play here. As those with several decades of solid mentalism experience under their belts will know, the audience will readily accept such a mix. They may have fun trying to work out what’s natural and what’s deliberate artifice in his act, but that’s partly what makes mentalism so beguiling.

If, however, our 40-year-old mentalist now claims to have been exercising his ability for only 5 years, then increasing the number of abilities on display makes B shoot way up, indicating that he should avoid the psychic end of the explanation spectrum.

In other words, the longer the experience, the more abilities it’s possible to claim and still appear convincingly “real” to an audience. After all, psychics are born, not made. With enough experience, each extra ability may be perceived as a different aspect of the same basic talent, which the mentalist has teased out over the years as he began to understand himself more fully.

There are other interesting aspects to the formula. It shows, for instance, that a 20-year-old can in fact claim ten years experience of one or more abilities, but that the audience will expect his talent not to be natural in origin but gained through practice. Because B is now 0.5, they may see it more as being a precocious natural aptitude for learning the trade of the mentalist backed by a desire to learn. That’s no bad thing, and it’s certainly believable to say that what he’s about to demonstrate is something he’s been obsessed by since an uncle apparently read his mind on his tenth birthday.

Also, even when you state that you’re using nothing more than trickery, thereby giving S a high value, if you have enough experience on display, the formula shows that increasing the number of abilities gives you scope for still being mistakenly perceived as the real thing. If you’re 40 with 10 years experience, with a stated ability approaching a full 1, and with 5 abilities in evidence, the formula gives a B of –0.25. Could this be why Derren Brown still attracts so many fans desperate to believe that he’s the real deal even after him being at pains to state that he’s not?

So, that’s the believability formula. Please don’t believe this formula is the holy grail of building a believable act, however. It’s a starting point; an idea offered simply as an objective “first cut” solution to the problem of opinion and counter opinion about age and experience in mentalism that seems to have gotten us nowhere fast.

Hopefully, what I’ve done is shown that by matching the explanation for your abilities to what an audience is prepared to believe about you, you’ll be well on the way to greatness. Of course, some explanations will become closed to you, but others will certainly open up. Does it really matter if your audience believe you to be the greatest exponent of body language since Desmond Morris rather than a genuine mind reader? They don’t have to know you’re actually using a swami, and neither should it matter. All that does matter is that they go home entertained and satisfied that what you say you do is what they think they saw.

Jon Thompson