Siffre Cave Study Psychology

Michael Siffre's Cave Study: Psychology

Michel Siffre, a french adventurer, investigated how the absence of external cues could affect biological rhythms, namely, how a lack of light may interrupt his circadian rhythm. Siffre spent months in a cave without access to daylight and found his circadian rhythm was notably disrupted.

Fig. 1 - Michel Siffre explored how a lack of light affects our circadian rhythms.

Siffre's Cave Study and Biological Rhythms

We have a regular sleep/wake pattern on a 24-hour day due to biological rhythms – internal biological clocks in our body that govern different bodily functions/cycles. Siffre was interested in how a lack of external cues could disrupt our bodily rhythms, namely, the circadian rhythm.

The circadian rhythm lasts for 24 hours. A well-known circadian rhythm is a sleep-wake cycle. This cycle is our pattern of sleeping and wakefulness during a 24-hour day. Everyone's sleep-wake cycle is different, and different things can affect the sleep-wake cycle, such as external cues.

These external cues are called exogenous zeitgebers, and the most notable one affecting the sleep-wake cycle is daylight.

Siffre's Cave Study: Summary

Siffre's cave study can be summarised in the following table. Here, we can see the timeline of what happened in the study and how Siffre attained his findings.

• Michel Siffre is an adventurer and scientist interested in the study of caves. In 1962, at 23 years old, he decided to live in a cave alone in the French Alps for two months, which was partly due to finding a glacier there sometime before he wanted to study.
• He then thought of living without any natural light, without knowing what time it was. So instead of studying the glacier, he ended up studying time. He spent his time in the cave reading, writing, researching, and thinking about the future. He settled into a sleep-wake cycle of around 24 hours and 30 minutes.
• He went into the cave on 16 July 1962 and came out of the cave on 14 September 1962. However, Siffre thought the day he came out of the cave was the 20 of August, showing how his time in the cave had warped his sense of time.
• Afterwards, Siffre also had other people participate in cave experiments but found their sleep-wake cycle was 48 hours. Siffre wanted to see if he could also get his sleep-wake cycle to be 48 hours. In addition, this was when people were starting space exploration, and Siffre thought his cave studies could help us know the experiences astronauts go through, which might be similar to being in a cave.
• So, in 1972, when he was 33 years old, he decided to live alone in a cave again – this time, for six months.

Siffre Cave Study in Psychology: Aims

The aims of the study were to find out what it would be like for astronauts in space, where there were no exogenous zeitgebers such as daylight to affect our biological rhythms. Siffre wanted to find out what his natural sleep-wake cycle would be without any exogenous zeitgebers.

Siffre Cave Study in Psychology: Procedure

On 14 February 1972, Siffre went into Midnight Cave, Texas, USA and stayed there for six months. He stayed in a tent with a bed, table, and chair.

• He took a supply of frozen food and 780 gallons of water into the cave.
• When Siffre woke up and thought it was daytime, he phoned the research team above ground, and they switched on the lights in the cave.
• He conducted daily experiments, taking his blood pressure, memory, and physical tests. When he felt tired, he thought it was then nighttime; he would phone the research team again, informing them he thought it was night and they would turn the lights off, and Siffre would go to sleep.

Siffre Cave Study in Psychology: Findings

After some time in the cave, Siffre became depressed and despondent at his lack of freedom. He was also excruciatingly lonely, he wanted to trap a mouse so he would have some companionship, but in the process of trapping it, he accidentally killed the mouse. In his own words, 'Desolation overwhelms me.'

In addition, his record player broke, and his books got ruined due to dampness. His condition was so dire that Siffre thought of suicide. His short-term memory, mental health, and eyesight all got worse.

Here is an account of his experience in the cave:

For the first 35 days, Siffre had a sleep-wake cycle of 26 hours.

On day 37, he stayed up for a few more hours and then slept long. This pattern of being awake and then asleep for a long time occurred periodically for the next month.

Then on day 63, he returned to a cycle of 26 hours. Nine weeks later, his sleep-wake cycle became more varied and random again for 20 days.

Sometimes it was 48 hours as the people in previous studies. When his sleep-wake cycle varied, the cycle could be from 18–52 hours. On day 150, he returned to a 26-hour cycle that lasted until the experiment's end.

Fig. 3 - Michel Siffre spent six months in a cave to study the sleep-wake cycle.

Siffre Cave Study: Conclusion

Siffre thought astronauts could manage their biological rhythm without exogenous zeitgebers; however, they would need companionship as the isolation would not be manageable. Siffre concluded that time is not something humans could work with and understand without any external environmental cues.

Michel Siffre Cave Study in Psychology: Evaluation

Let's look at the strengths and weaknesses of Siffre's (1975) study.

Siffre Cave Study: Strengths

First, let's explore the strengths of Siffre's cave study.

• The study produced a lot of quantitative and qualitative data.

• The study was done over a long time, six months, which allowed Siffre to investigate his sleep-wake cycle and show how irregular it became.

Siffre Cave Study: Weaknesses

• When Siffre woke up, strong lights were put on, and when he went to sleep, they were turned off. The lights could have acted as an external cue, which affects the study's internal validity.

• Siffre was the only participant in the study, so it is hard to generalise his findings, such as how he did to astronauts.