Should you believe in ghosts?

Indulging in costume shopping and carving pumpkins, laughing at paranormal investigators on our TV screen jumping at a breeze or ridiculous ghost stories told over sleepovers is all in the spirit of Halloween.  However, while some like to scare themselves silly for a laugh over the festive period, nearly half (43%) of UK adults believe in, and are fearful of, the paranormal. The top reasons the British believe there may be an uninvited guest at in their home include mysterious unexplainable sounds, cold spots, and even shadowy figures.

Many scientists have dipped their feet into the murky waters of the paranormal – so can science provide the evidence for the existence of ghosts?

While nobody has managed to capture a ghost in a controlled environment as evidence of its existence, in 1901 Dr McDougal tried instead to prove the existence of the soul. He investigated the idea that the ‘soul’ was physical enough to cause a drop in mass in humans at the moment of death – he pinpointed a 21 -gram loss which he concluded, influenced by his pre-existing beliefs, to be the mass of a soul .

43% of UK adults believe in, and are fearful of, the paranormal.

However, his findings were not welcomed with open arms by the science community, with many theories soon later proposed that diminished the credibility of his study. One key objector was Psychologist Richard Wiseman who pointed out that the human body at the point of death heats rapidly and so the loss in mass could be due to the loss of fluid via sweating. So, with a lack of credible evidence in the science field, the soul of a former 19th century resident most probably isn’t the source of the flickering lights and sudden gusts of wind!

But how do you explain the vivid ghost sightings people have experienced?

The most common explanation is sleep paralysis. Cambridge neuroscientist Baland Jalal explains sleep paralysis as being “like dreaming with your eyes open”. The phenomenon occurs when a person regains consciousness whilst in the rapid eye movement (REM) stage of sleep. Outside of the REM phase, there is an increase in parasympathetic tone – inducing the body to relax. However, during phasic REM sleep, there is an upsurge of sympathetic tone, preventing muscles from contracting in response to dreams. If you wake up during this phase, the muscles might still be unable to move, leaving you effectively paralysed.

Waking whilst still in the REM phase creates a dissociation between perception and motor function, which can result in and have often been accompanied by hallucinations.  So, when someone reports of a paranormal “haunting” that left them so terrified they were unable to move, a scientist’s diagnosis would most likely circle back to sleep paralysis.

Currently, no conclusive evidence has been brought forward to support the existence of supernatural creatures. However, discoveries are made every day and some scientists have dedicated whole careers to finding the evidence. In science, non-existence is rarely provable, so maybe that occurrence you can’t explain might just have been caused by the supernatural…