Boys will always grow to be taller than their mother

Is this true?

I heard this a few times, stated as a fact. All male children will grow up to be taller (or at least the same height) as their mother. No Male child will be shorter than their mum.

Excluding Dwarfism or malnutrition as possible causes, I just can’t see it. If Mum is an Olympic basketballer, 6’3" or taller and Dad is a shortarse 5’2", doesn’t the boy have a reasonable chance of being shorter than Mum?

Any facts on this or just peoples experience?

Usually, yes. Always, no, far from it, especially if, as you surmise, the father is shorter than the mother (although, of course, that doesn’t happen often, both because men tend to be taller on average, and women tend to prefer men taller than themselves, and men tend to prefer women shorter than themselves). There is, I believe, a formula for predicting a child’s adult height from that of its parents: I think you take the average of the parents’ heights, then add a factor for a boy or subtract one for a girl. Of course, that only works “on average”: it gives you a tendency, probably the median of a normal distribution, not a definite prediction. Height is determined by a whole lot of different, interacting genes (and, of course, environmental factors, in the womb and after). This makes definite predictions impossible, in practice.

Add to the factors already put forward …average heights have been increasing for a number of decades, and people tend to shrink a little as they get older. So when the boy hits eighteen and his mum’s, say 40 or 50, she’s probably already down a cm or so from her prime, and hence easier to beat, height-wise.

The other add-on that I’ve heard to that saying is “…and a girl will always be shorter than her father.” That bit’s definitely false (said the 5’10" chick with the 5’9" dad)

Mind you, the whole thing in the parenthesis is hard when the dude is 1’30m, as one of my former classmates (I have other ex-classmates of similar heights, but female; it’s not too uncommon for this area). His sons have the same shiny-blonde hair, the same blue eyes, and look to be as short as Daddy when they’re done growing. It’s not dwarfism, they just happen to be on the tail-end of normal. I know (via my former classmate’s mother, who has 10cm on her son) that they considered HGH therapy for the kids but decided against it.

Add 5 inches to a woman’s height to figure out how tall she’d be as a male at the same percentile. The son is pretty likely going to end up inside the range between that number and Dad’s height. So Dad has to be more than 5 inches shorter than Mom for there to be even money that the kid will end up shorter than Mom. The formula is referenced as the “Mean Parental Height” and for boy’s is (Height of mother plus 5 inches plus Height of father)/2.

A rule-of-thumb formula for predicting a child’s adult height is as follows (in contemporary American society):

For a boy, add 5.4 inches to the mother’s height. Average this with the father’s height. This is the most likely adult height for a boy.

For a girl, subtract 5.4 inches from the father’s height. Average this with the mother’s height. This is the most likely adult height for a girt.

These are most likely heights, not absolute predictors. There’s probably a distribution with a standard deviation of about two inches or so (although I’ve never read anything that gives the standard deviation for this distribution). That means that two-thirds of the time the actual height will be within two inches of the height calculated above and 95% of the time the actual height will be within four inches of the height calculated above. I added the words “in contemporary American society” above because there has been a variation in the average height of people in various places and various times. Men have always been taller than women but by various amounts, not always by 5.4". Average heights have increased a little bit over time in most societies in modern times.

So if the father was 5’4.2" tall and the mother was 5’11.6" tall, the most likely height for a son would be ((5’11.6" + 5.4") + 5’4.2")/2 = (6"5" + 5’4.2")/2 = 5’10.6" tall. So this is a case where the son would probably be a little bit shorter than the mother.

You may feel free to ignore any rules that people give you that say, “X will always be more than Y (in some scale)” when they don’t cite actual numbers.

Any rule with the word “always” in it is always wrong. Even this one.

Interesting calculations.

My mother is 5’2", my father was 6’1".
I am 5’3".

My son’s father was 5’2".
His mother is 5’ and his father is 5’7".

My son should be @5’5" but he is 5’10".

It is interesting. Both my parents were 5’6".

I’m 6’3"

My father is 5’ 8".
My mother is 5’ 6".
I (a full grown man) am 5’ 6".

So the answer is no. A boy will not always be taller than his mother, even when his father is taller than his mother.

Right. “Pretty likely” is a long ways off from “always.”

Also that mean parental height tool is known to fall down some when parents are either very short or very tall - there tends to be some regression to the mean.

The calculation works well for my brother (within a quarter of an inch!) but I’m shorter than both of my parents who are 10" apart in height, so it clearly doesn’t work out for me since I’m close to 3" shorter than it predicts.

I am half an inch off 6ft. My son’s father is 5ft 2". My 15 yo son is about 1 inch shorter than myself and still has a couple of years growing left, so Im assuming he will be taller than me when he has finished.

I am 5’5" and my husband is 6’1". A daughter’s predicted height from the formula given above would be around 5’6 to 5’7". We have four daughters whose heights are 5’3, 5’7", 5’9" and 5’10". Seems like we are a bit outside the likely standard deviation at both ends.

My grandfather was 5’10 and my grandmother was 5’9". Several of their 10 children were around that height or taller, but some were significantly shorter. One daughter was 5’1". One of the sons was 5’5". So looking just at that one family, no, sons are not always taller.

I’m 5’4’’ and my daughter’s dad was 5’7’’. She is 5’9" so presumably something went wrong somewhere.

Vast majority of times, yes. There are exceptions. My mom is about 5’1, dad is 5’8. I am about 5’9, slightly taller than my dad but much taller than my mother. My brother is 5’11.

Care needs to be taken when using or interpreting “always”. In usual discourse, it means “unless there are extenuating circumstances which override the tendency described”. In this case, of course, some boys will not grow up at all, and die in infancy. There isn’t anything that boys will “always” do. Nevertheless, “always” remains a useful word when nitpickers are excluded from the conversation.

The gray area between “always” and “pretty likely” is subjective.

A good friend of my mother’s was about 6’2". Her father, whom I knew, was about 5’6" and her mother (who died young) was, according to my mother, was about 5’. She married a man who was about 6’4" and had a daughter who was 5’7". The woman had at least one other anomaly, though. She had a man’s voice and I would describe her as handsome, rather than beautiful. Presumably some kind of hormonal overproduction.

I never quite made 6’1" and my wife is 5’5", but both our sons are 6’2". Our daughter is 5’6", which is probably within that formula.

Kids end up, generally, between the range of their parents, so a 6’ woman and a 6’2 man will generally have sons who are taller than their father (the mother’s range is “unusually tall,” while that father’s is just “tall”), but their are tons of things that affect height. My brother is a lot taller than my father, and while it’s true that my mother is a little taller than average for a woman, my brother also probably gets some recessive genes from my father, because he has a tall brother. My paternal grandmother, who was only 5-even had a very short mother, but a very tall father (there’s only one picture in existence of them side by side, and she seems to be wearing heels, and yeah, she’s a lot shorter. My paternal grandfather was only about 5’7, though. I don’t know how tall his biological father was, because he died when my grandfather was 5 years old, and there are no pictures of him.

I’m only 5’5, and while my husband is 6’2, our son is on his way to becoming much taller than 6’2. He’s nine years old, and already 4’11, which puts him above the 99th percentile for his age. When you see him with his class at school, he looks out of place. I’m actually kind of hoping he won’t have an adolescent growth spurt, because if he keeps growing at the rate he’s growing, plus puts on five of six inches in just a couple of years when he’s 15-16, he could end up being 6’7.

But at any rate, those are recessive genes. My husband’s mother is very short, so he is a little shorter than his father, who was 6’3, and my great-grandfather on my mother’s side was 6’4, and born in the 1880s. So we have genes all up and down the charts, but the boychik seems to have gotten just the tall ones (FWIW, his doctor says there is nothing wrong with him).

But yes, it is typical that, barring disease or abnormalities like a form of dwarfism, a man will be taller than his mother. As noted, it is also typical that a man is taller than his wife. In couples where the man is shorter, all bets are off.