The term "latchkey child" may date back to World War II, but even today thousands of older children are home alone between 3pm and 7pm. So what does the experience do to a child?
Sandra Fletcher was just five years old and about to start infant school in 1944, when her mother told her she wouldn't be around at the end of the school day.
It is difficult to imagine children as young as five making their own way home from school and letting themselves into an empty home. But that was the reality for many children during the war.
One theory has it the term "latchkey child" was actually coined the year Sandra started school - in an American TV documentary about the increase in children being left at home, alone.
Britain was witnessing a similar phenomenon. With fathers away fighting, mothers had no choice but to go out to work. Childcare wasn't always available.
Sandra, an only child, would be a latchkey child throughout the rest of her school years.
"I used to wear the key around my neck on a piece of string," she recalls. "It was about three quarters of a mile from school back to my home. I just let myself into the house and waited for my parents to get home.
"Sometimes I would bring my school friend home. I even used to get them to make the beds and tidy up - my mum would have had a fit if she'd known."
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Actress Jessica Hynes (pictured), a latchkey child from the age of six, presents Latchkey Kids on BBC Radio 4 at Wednesday, 26 May at 1100 BST
But if today the idea of leaving young children alone in a family home is frowned on, then it was viewed more sympathetically, says historian Pat Thane.
"People understood that mothers were supporting the war effort and shouldn't be criticised," she says.
Yet by the late 40s and 50s, the mood had changed. There was a moral panic about mothers not spending time with their children, which was generated by the work of social psychologist, John Bowlby.
His ideas, based on studies of very young children in institutions whose parents had died or separated, led him to a disturbing theory. Separating young children from their mothers too much, he said, would lead to terrible psychological effects in later life.
This became generalised to cover older children - particularly those of working mothers - which led to criticism, as well as a great deal of guilt on the part of the mothers.
However many mothers had little choice but to work. And as working mums became more common in the 60s and 70s, the phenomenon of the latchkey child returned, according to a report by the campaign group 4Children.
Smoking at 12
Lizzie Sleaford was among this "second generation" of latchkey children.
Born in 1977, from the age of 12 Lizzie and her older sister were left to their own devices as their mother became increasingly busy running a residential home for the elderly.
"I was absolutely appalling as a teenager - I was a complete delinquent. I can't blame all these things on my mum though.
"Her hours were very long and often during the night. We would come home from school, find a packet of crisps, turn the telly on, amble around the house, avoid homework as best as we could, and generally get up to mischief, like smoking at the age of 12."
The experience has led Lizzie to go completely the other way in her approach to parenting.
"I am a 1950s-style housewife," says the now mother-of-two. "I made the decision that my children would have me at the end of school and I am always there to pick them up. They have a dinner every night and I'm there at school plays and do all the things that my mum wasn't able to do because she had to work."
The issue of latchkey children has not gone away.
The problem hasn't gone away
While there is more childcare for younger children today than before, a report earlier this year said thousands of older children are alone at home between 3pm and 7pm. The report by the charity Action for Children suggested such children run a higher risk of delinquency.
The report found that as 80% of mothers of 11- to 14-year-olds are in work, parents often either leave their children home alone or patch together informal and often unsatisfactory arrangements with family and friends.
The law offers some protection to children. While there is no legal age limit at which children can be left alone - it's an offence to leave children on their own if it places them under risk.
Like Lizzie, Sandra reacted to her latchkey experience when she became a mother, striking a secret pact with herself to stay at home at least until her children went to school.
She went on to have three children and feels fortunate to have been able to keep her wishes. But it came at a price.
A qualified teacher, she was away from her profession for 10 years and it wasn't until her youngest was at school that she decided to return.
"I think this made my career suffer. I remember having an interview and they said to me "you'll be so out of date now you wouldn't be any good to us in the teaching profession.
"I remember thinking 'I'm not 40 yet and I've had it'. But that's the other side of the coin."
Below is a selection of your comments.
Interesting to read the article and it almost sways against 'latch-key' in its tone. My daughter now 12, has had a key since senior school last year. She is trustworthy, reliable and her mum has no issue with her being responsible and practical - safety included - plus by the time she does after school clubs and visits grand parents once a week, the five afternoons are gone. I was a latch-key kid as my parents had no choice - there's even less choice these days and worse times to come with the economic situation. Managed properly and the responsibility it gives kids, its a powerful growing up tool for them.
My kids from the age of 9 would get home on their bus about 1 hour before me, but there was no slacking. Each day a list of chores was put on the board in the kitchen, they had to do those and their homework. Rewards were good for ensuring that things were done, privileges withdrawn and other assorted punishments meted out if they didn't. Now in their 30's they have been able to live independently and successfully, have professional careers and are good cooks. They may have been "latchkey kids" but they were taught responsibility, independence and respect.
From about the age of nine, I would walk myself home from school, up until I finished my A-levels and left for university. I'd often be at home alone and sometimes with my younger brother until 6pm when my mum would get in. I really don't think it's a big-a-deal as is suggested in this article. It teaches responsibility and independence. Obviously it does depend on the child but I think in most cases this experience can allow the child to develop into an autonomous being: too many children are spoon-fed and cannot look after themselves properly when they leave home. I am 20 this year so I am a more recent example of this kind of upbringing.
Alex, London, UK
I was a "latchkey" kid in the late 50's/early 60's. I came home from school, I wasn't allowed friends around, I did my homework then had simple chores to do (hoovering, kettle on etc), before my mum arrived home from work, then I could meet up with friends. I think something could be learned from this regime.
A 12 year old shouldn't need their mother around all the time! From the age of 12 I was always in after school on my own with siblings, and we were perfectly happy and have all grown into highly successful happy adults in a very close family. We enjoyed the couple of hours before Mum got home playing, reading, doing homework etc. I always felt it was important that we had the time to learn to be independent adults and have a bit of responsibility. By 14 we would often be getting the dinner started to help out our parents.
Jo Blogs, London