Old wives' tales: Fact or fiction?

Old wives’ tales. Most people would have heard one or two as they grew up, that old matriarchal wisdom passed down through the ages. 

While some are clearly furphies, an ulcer on the tip of your tongue means you’ve been telling lies, others seem as though they would hold some kernel of truth. 

But do they hold up under a scientific microscope? Is there really any truth behind these old wives’ tales?

This is what the science has to say on three popular ones. 

Red sky at night shepherd’s delight, red sky in the morning shepherd’s warning. 

It’s one of those things your grandma says to you, “Pack your coat today it was a red sky this morning, shepherds warning”. 

The old weather saying actually first appears in the Gospel of Matthew, and its general wisdom denotes a red hue in the sky in the morning means you’re in for a day of bad weather, while a red sky the night before heralds a fine day ahead. 

There are variations on the saying, sometimes it sailors not shepherds, but the meaning is all the same. 

Scientifically, the phenomenon is most likely to be accurate if you are in an area where the prevailing weather comes from the West, where the sun sets, as it does in Tasmania. 

The red hue in a sky is caused when the blue light coming from the sun is scattered by particles and dust in the atmosphere, trapped there by a high pressure system, leaving only the red light to come through. 

When there is a red sky at night the chances are tomorrow will be fine as it means there is a high pressure system, bringing good weather, coming from the west where the sun is setting. 

Similarly, if there is a red sky in the morning it means the high pressure system has passed away to the east, most likely making way for a low pressure system, with its wind and rain, behind it. 

So, if there is a red sky in the morning probably pack your coat just in case. 

People go crazy on a full moon. 

It has been a long held belief that on nights of the full moon people’s behaviour goes wild. 

There are mountains of anecdotal evidence of increased crime rates, patients in psychiatric hospitals becoming unmanageable and animals going batty. 

The superstition heralds as far back as the middle ages when it was believed changes in the moon’s phases could cause madness and insanity. 

The word lunatic even comes from the latin word for moon, luna. 

But, it seems the idea is in fact a myth. Multiple studies looking for a link between the full moon and increased rates of hospital admissions, psychiatric disturbances, crisis calls and criminal activity have failed to find a connection. 

An examination of 37 studies on the topic found no more than a 1 per cent of variance in activities associated with lunacy in different phases of the moon. 

So what explains this long anecdotal history of the phenomenon?

This could well be a case of confirmation bias, which is a tendency to interpret events in a way that confirms one's own beliefs. 

So someone who believes people go crazy on a full moon is more likely to notice unusual behaviour when there is a full moon, thus confirming their own belief. However, when it isn’t a full moon they are less likely to notice unusual happenings and thus believe they aren’t occurring. 

Additionally, believed links between a full moon and odd occurrences could be fail to take into account other cycles that may have an influencing factor over people’s behaviour, such as weekly cycles. 

An apple a day keeps the doctor away. 

Is this saying really one of those your mum just tells you to make you eat your apple?

Well, yes and no. 

A study by the University of Michigan tested the saying and found there was no statistical decrease in visits to the doctor for people who ate an apple daily. 

However, there are other studies that show an increase in health and a decrease in mortality rates for daily apple eaters. 

A University of Western Australia study of 1456 participants showed those who ate more than 100 grams of fruit, or the equivalent of a small apple, each day were likely to have a longer life expectancy than those who didn’t.

While the study looked at apples, other fruits are likely to have the same effect but apples are a highly consumed fruit. 

Research found flavonoids, a common plant pigment compound which apples are rich in, improve blood vessel relaxation, which may help battle high blood pressure and heart disease. 

Research has also showed there are a range of other health factors which play into the likelihood of needing a doctor's visit, with apple-eaters being linked with having generally healthier lifestyles. 

This isn’t necessarily a causal link however, it could mean that people who are more conscious about their health eat apples. 

The story, Old wives' tales: Fact or fiction?, first appeared on The Examiner.