Love Island: Is the lie detector test fake?

Fincham's 'lies' may have been due to nerves rather than outright deception

Fans of Jack Fincham and Dani Dyer’s budding relationship were left devastated after the lie detector test episode showed Fincham failing a number of questions.

The favourites to win Love Island, Dyer has previously discussed the honesty and loyalty she expects and requires in a relationship after previous boyfriends lied and cheated, while Fincham has had to confess to his own history of cheating.

The daughter of EastEnders actor Danny Dyer didn’t receive the answer she wanted to hear when Fincham responded to a series of questions while attached to a lie detector.

“Any girl in the world if they’ve got that question and their boyfriend got it wrong they would be upset,” Dyer tearfully says.

However, lie detectors aren’t completely reliable - so there may be hope for the couple.

Lie detectors - or polygraph tests - are designed to be capable of detecting deception through “analysis of physiological responses to a structured, but unstandardised, series of questions,” according to the American Psychological Association (APA).

By monitoring heart rate/blood pressure, respiration, and skin conductivity, the instrument can supposedly determine whether the wearer is telling a lie - as it is assumed that lying causes stress.

Fincham's answers may end the couple's relationship (ITV Love Island)

When we lie, it is expected that our bodies will betray us through increased heart rate, sweating, or other noticeable reactions.

But the validity of polygraph testing is often debated - with the general consensus being that lie detector tests are inaccurate.

The main reason for the disbelief in the tests stems from the fact that there is no single way to lie.

Dyer has expressed her need for honesty and loyalty in a relationship (ITV Love Island)

Although there may be certain indicators that can hint at deception, there is “no evidence that any pattern of physiological reactions is unique to deception,” according to the APA.

Some people may sweat when they lie, but others may have no reaction to deceiving people - especially as people can become immune to the reactions.

Jack's answer triggers a lie (ITV Love Island)

Certain triggers such as increased heart rate may also occur during moments of anxiety, such as if your relationship depends on the answers of a lie detector test, and not just in cases of lying.

Despite the room for inaccuracies, the National Polygraph Association defends lie detectors and states that scientific evidence has found an 87 per cent accuracy rate.

Hopefully, Fincham was just nervous when he answered questions about his feelings for Dyer.