Welcome To Holland

I am currently working through a FutureLearn on ‘the genomics era’. The course introduced some of the genetic errors that can happen in certain diseases.

One of the errors occurs when cells divide to form reproductive cells (sperm or eggs) – a process called meiosis. Most cells in the body have 46 chromosomes, arranged in 23 pairs. Reproductive cells have half the number, so that when a sperm and egg fuse, the newly fertilised cell has the normal complement of 46.

Certain diseases, like Down syndrome, Edwards syndrome and Patau syndrome, are the result of an extra chromosome in the fertilised egg. So instead of 23 pairs, there are 22 pairs and one triplet (or ‘trisomy‘). This error occurs when the reproductive cells are made, if the chromosomes of the parent cell are unevenly split between two new daughter cells.

The course featured a moving video of two parents whose daughter was diagnosed with Down syndrome. The father explains a powerful analogy to capture the emotions and experience of being told of such a diagnosis. The essay, ‘Welcome to Holland’ written in 1987 by Emily Perl Kingsley about having a child with a disability, is narrated in the video below, and is incredibly touching.

Calling all science-y parents

It’s been a while since I posted on The Skeptical Dad. Since around the time our second one – a sceptical daughter – came along, in fact.

It turns out that having children vastly diminishes the time and energy for properly researched blogging. Or for anything, for that matter.

Who’d have thought?

I’ve got a stack of ideas jotted in random places and half-written posts waiting to be worked on. So I’ll get back to regular postings from now on.


For now, here are a few things I’ve noticed in the last year or so, which might be interesting to science-y parents.



From The Royal Institution, the UK organisation dedicated to scientific education:

ExpeRimental is a series of short films that make it fun, easy and cheap to do science at home with children aged 4 to 10. Our films give you lots of ideas for kids’ activities that will help you explore the world around you, question and experiment together. We’ll show you how to do the activity and how to make sure adults and children get the most out of it. Tell us how you get on and share your photos and any funny things your kids say!

What I like especially about ExpeRimental is that it’s not just a series of fun activities (though it is) but it teaches a real scientific approach. By tweaking variables, predicting what will happen, then observing the effects, it takes these practicals from demonstrations to experiments.

Citizen science

The brainchild of Sophia Collins and funded by The Wellcome Trust, Nappy Science Gang is taking a citizen science approach to answer some key questions.

…it will be the first citizen science project where the users set the research priorities, design their own protocols (with advice from scientists) and then run their own experiments. We’ll find out some useful science for cloth nappy users (a growing group as the environmental imperatives become clearer), and we’ll tackle a lot of persistent urban myths, with scientific thinking and evidence.

Find out more and get involved at the Nappy Science blog and Facebook page.

Introducing kids to evolution

Here’s a great resource for books on evolution and Charles Darwin aimed at kids, courtesy of Evolution for Kids!


Happy science-ing!

Does breastfeeding ‘cut leukaemia risk’? No good evidence

Occasionally my work and home life collide – I read some stories in the press about research claiming breastfeeding for six months or more could cut the risk of childhood acute leukaemia. The research was shaky, so I wrote this for the Leukaemia & Lymphoma Research blog (where I work).


Reports coming out in the media (such as Express, Mail, Mirror) are suggesting that breastfeeding for six months or more can lower the child’s risk of developing leukaemia. But where did these findings come from and how reliable are they?

In this post, we take a look at the research that led to these reports, and suggest that the results are not very robust, the conclusions are overstated and the claims likely to cause unnecessary alarm.

Greater than the sum of its parts?

The new research, published in the peer-reviewed journal JAMA Pediatrics, combines many previous studies that looked at whether children who had been breastfed (and for how long) went on to develop childhood leukaemia. The studies in the new analysis were a mixture of size and quality, so on their own couldn’t lead to any definitive conclusions. But when put together and re-analysed – known as a meta-analysis – it is intended to boost the power of the findings.

The new study includes 18 studies that met a certain quality threshold. The researchers, based at University of Haifa in Israel, report that children who had been breastfed for six months or more had up to a 19% lower risk of developing leukaemia than children who had never been breastfed or had been breastfed for under six months.

From this, they conclude this is sufficient evidence of a protective effect to further promote the health benefits of breastfeeding and encourage greater uptake amongst new mothers.

But we are not persuaded these claims truly stack up.

Correlation is not causation

The strength of a meta-analysis is that it tries to make sense of all the best research on the subject. But all of the studies within the new analysis looked at the association between breastfeeding and leukaemia, and therefore cannot tell you about true causes. Other background factors that affect both the likelihood of breastfeeding and leukaemia risk could have been missed or overlooked.

For example, parental affluence may affect the decision to breastfeed. But affluence will also affect a host of behaviours, like attendance at nursery, exposure to infections, decision to vaccinate, time of weaning, and many, many more. We don’t know for sure what factors do influence leukaemia risk – and parental affluence is just given as an example here merely to illustrate the complexity of background factors – but simply linking breastfeeding and leukaemia risk without consideration of other potential influencing factors is far too premature.

Experts who conduct these types of studies are well aware of these issues and always attempt to account for background factors, like socio-economics, lifestyle, gender, ethnicity, and so on, but it’s always hard to eliminate them altogether. Nevertheless, we were alarmed when we spoke to our statistical experts who noticed that the meta-analysis unusually relies on crude data that did not appropriately account for background factors.

They suggested that the authors’ relative inexperience with this type of analysis has led to a number of flaws.

Hidden biases

The experts we spoke to pointed out a gross error in the data – one dataset, that had been used in two different publications, is included twice. This could distort the statistical robustness or the size of any effect, and could be serious enough to consider a correction or withdrawal of the paper.

There are also a few ways these data could have been skewed to give wrong or exaggerated results. One is a bias in those participating in these studies. Many were based on phoning mothers at home or by a self-administered questionnaire. This introduces a potential participation bias, where the people surveyed and who agreed to take part were not representative of the population as a whole. This may mean certain groups, such as more educated or time-rich parents, were overrepresented in the comparison group (children who didn’t get leukaemia), suggesting a larger proportion of children who did not get leukaemia were also breastfed.

Almost all of the studies asked mothers or parents to remember the duration of breastfeeding, sometimes many years later. This introduces a possible recall bias, where parents may not have accurately remembered what they did or their responses were affected by knowing that their child had had leukaemia. And because childhood acute leukaemia is thankfully relatively rare – only three to four children in every 100,000 are affected each year in the UK – the small numbers could have inflated these biases.

It would be far better to recruit a large random sample of people, collect data in real-time, and then look at whether children went on to develop leukaemia. This is more costly and time-consuming, but it would help diminish some of these potential biases because the particpants and research questions would be defined up-front. 

The authors acknowledge these limitations in their discussion section of their paper, which is why we were surprised by the strength and certainty of their claims in the conclusions section.

What would this mean in the real world anyway?

There is some evidence that links proper immune system development to a reduced likelihood of developing leukaemia as a child and certain genetic faults present at birth can raise the risk substantially, but we are still far from truly understanding all the many different factors at play. It is an important area to be able to understand who is most at risk and what factors can alter their likelihood of developing this disease if we are to prevent some of these cases, but we are not convinced that this new analysis provides strong evidence for a significant role of breastfeeding.

We should also stress that because of the relative rarity of childhood leukaemia, even if the authors’ claims were true, it would still affect only a tiny number of children. And it would still only affect children who are already at risk because of key genetic faults that occur in the womb.

There is a lot of pressure on new mothers, some mothers cannot breastfeed and many factors can affect how long new mothers can breastfeed for. Parents of children who develop leukaemia can also feel a lot of guilt, even though we know some children will unfortunately get the disease whether they’ve been breastfed or not.

Stories based on problematic research do not help anyone.

  • For some expert opinion, including our Research Director and Prof Eve Roman (an epidemiologist whose work we support), see the Science Media Centre
  • Reference: Amitay & Keinan-Boker (2015). Breastfeeding and Childhood Leukemia Incidence A Meta-analysis and Systematic Review. JAMA Pediatr. 2015;169(6):e151025. doi:10.1001/jamapediatrics.2015.1025

What can Mickey Mouse tell us about a growing child?

At a party some time ago, I got talking to a biology graduate friend about comparative psychology, as a geek tends to do at social occasions.

Comparative psychology is the study of animal behaviour and mental processing across different species. By doing this, it gives us clues to the function, benefit and development of a particular behaviour. Understanding the similarities and differences amongst different animals in this way can shed light on evolutionary relationships.

The topic came up because our friends were revelling in how cute baby animals are. If you don’t believe me, just look at these cherry-picked examples:

Author: George Estreich

Baby monkey

Author: Ville Miettinen

Baby fur seal

Author: Matt Stanford

Baby elephant

Author: uaeveggies

Baby duck

What’s striking is how wildly different baby animals can provoke the same “aaah” reflex. Baby primates and baby birds, separated from each other and from us by millions of years of evolution, can elicit the same cooing reaction. And size doesn’t seem to matter − a 100kg baby elephant can bring as much infatuation as a 5kg baby seal.

In other words, there’s something about being a baby, and not just a miniature version of an adult.

This immediately reminded me of an image drawn by Nobel prize-winning animal behaviourist, Konrad Lorenz. It shows how juvenile proportions are conserved across different animal groups, and goes someway to explain why we react to many baby animals as we do.

From Studies in Animal and Human Behavior, vol. II, by Konrad Lorenz, 1971. Methuen & Co. Ltd.

From Studies in Animal and Human Behavior, vol. II, by Konrad Lorenz, 1971. Methuen & Co. Ltd.

I think I first saw this image in a book by renowned evolutionary biology, Steven Jay Gould*. He also included it in a wonderful essay called Homage to Mickey Mouse. In this article, Gould explains that over time, to chime with his softening of character, Mickey’s appearance became increasingly juvenile.

via Zoonomian

A large head relative to body, short legs and feet, bulbous cranium and big eyes, as seen in a latter-day Mickey, look like the hallmarks of a juvenile. And Mickey travelled this path to juvenility in reverse − a phenomenon known as ‘neoteny‘.

An illustration’s fine, but to truly demonstrate this scientifically, Gould actually measured the relative changes in Mickey’s physical attributes and plotted the results on a graph. The result, as was Gould’s wont, is an engaging fusion of science and creative writing − do read it. (On reading, I did wonder whether Mickey’s appearance was altered to match a desired change in character, or the other way round.)

The key to all this is that the proportions of a baby’s face, as compared to an adult, are similar across many different animals. This set of features triggers what Lorenz described as an ‘innate releasing mechanism’ − an automatic and consistent reaction to an important behavioural cue. It makes sense that a hard-wired mechanism has evolved to trigger an immediate sense of attachment when confronted with a baby’s face − it will promote parental care, which has clear evolutionary advantages.

But that same hard-wired mechanism also appears to fire when we see similar baby-ish proportions in other animals. It’s an inappropriate response in an evolutionary sense, but it’s better to be harmlessly fooled by a baby bird than to not feel instinctively drawn to our own baby.

What’s fascinating is that, in some cases at least, these ‘releasers’ are reduced to very specific features. A classic example was demonstrated by Lorenz’s Nobel prize-winning collaborator, Niko Tinbergen, using three-spined sticklebacks. A male stickleback will attack another male, as identified by a red belly, but will also attack any object with a red spot − fish-shaped or otherwise. A stickleback-shaped object without a red belly is suitably ignored. Like a red rag to a stickleback, it’s better to be safe than sorry.

Babies do something similar in reaction to stylised smiley faces − a circle for a head, two dots for eyes, and a curved line for a mouth is enough to grab a baby’s attention. This stays with us into adulthood and is, for better or worse, the reason why emoticons are so enduring. So, similar to a stickleback reacting solely to a red spot, it seems it’s not a whole baby’s face we respond to, just a certain set of features.

Yes, your baby’s cute because of this graph:

“At an early stage in his evolution, Mickey had a smaller head, cranial vault, and eyes. He evolved toward the characteristics of his young nephew Morty (connected to Mickey by a dotted line).” By Steven Jay Gould

* I should dedicate this post to the late, great Derek Yalden, who taught me zoology at The University of Manchester and told me to read The Panda’s Thumb.

(As an addendum: none of this makes animals we find cute any more ‘worthwhile’ than “ugly” animals. Check out the recent campaign by the “Ugly Animal Preservation Society“.)

Looking after kids: it’s lovely but is it work?

Last week, I sent this tweet:

My wife had gone on a well-earned break for the day with a friend, leaving me in sole charge of our two-year old son and five-month old daughter.

We spent the morning around the house, slowly getting dressed, fed, washed and dressed again (we have a five-month old, remember). Finally, blessed with some gorgeous weather, we made it to the local park in the afternoon, before back for tea, bath and bed. Phew!

My point, squeezed into a snippy 140 characters, was in reaction to those who can be heard saying something like: “I put earplugs in/don’t do the night feeds/need lie-ins at the weekend (*recycle as appropriate) because I’m the one who has to go to work.”

I’ve certainly heard it. In my experience, always from men, many of whom I’m fond of and respect. I assume that when it is said, it’s usually from men, given the societal bias for women to take the extended parental leave, though I’m relying mostly on anecdote and supposition.

But, as I was changing the fourth nappy (diaper, my American friends) of the day with a two-year old playing ‘horsey’ on my back, I thought: “this feels on awful lot like work”. And at my office, I can make regular cups of tea, zone out for five minutes to check the news/Twitter and (usually) go the toilet when I want. I would like to see the bladder infection rates amongst parents, because I find myself ‘holding it in’ an awful lot.

From Men’s Health News

Don’t get me wrong, I had a lovely day and adore spending time with my kids. But it is hard graft.

Which is why this attitude really grates. My wife, who is currently on her second period of maternity leave, looks after the kids for the five working days, with our two-year old being at nursery school (preschool, my American friends) a couple of mornings the only partial respite. I did it for one day and felt the pinch.

But as Ian Curtis sang, routine bites hard. Day after day, going through those endless cycles of nappies, changes of clothes, feeding, shushing to sleep, is draining. And when you’re drained, doing it all over again sets up a tiring negative feedback loop.

This becomes even more acute when one considers that stress and lack of support can increase the risk of post-natal depression. Even without leading to such extreme consequences, it is beneficial for a child’s development for the parents to be less stressed. In fact, one study showed that minor daily hassles, which all mothers experienced regardless of background or family set-up, were related to more child behaviour problems, less satisfied parenting and poorer functional family status. The study also emphasised maternal emotional support, either from friends, communities or partners, as an important buffer from these adverse effects and to maintain mothers’ psychological well-being. I can’t even begin to imagine what it’s like to be a single parent, but find my anger rising as society moves to remove support for this group.

Again, I should say, we both get so much joy from looking after them and wouldn’t change them for the world. But it IS hard graft, and is why my wife’s break was more than fully earned.

Obviously, everyone’s situation is different. Many, many partners who ‘go to work’ are committed to helping a stay-at-home partner in the evenings and at weekends. Many people’s work is also incredibly demanding and stressful (more than mine), and this post is not a prescription of what ‘working’ parents ought to do, as it will depend hugely on circumstances.

But if you find yourself justifying an act with, “well I’m the one that works”, then you may want to have a second think.

My feedback for First Great Western trains

Excuse me for deviating from talking about science for a minute, but I need to vent.

I tried to make a complaint to the train company, First Great Western, about the lack of baby changing facilities on their trains. Apparently, my feedback “contains content that may present a security risk” and I was told to “enter more appropriate information” to allow me to submit.

I have absolutely no idea what content was inappropriate and, after 3-4 attempts, had no desire to go through a further lengthy trial-and-error process to push through a simple letter. So I have posted it below. (If anyone can point out the security-threatening content then please do!)

I hope someone from FGW is able to respond:

I took the 0859 to Bath from Brighton (3+ hr journey) on 17th May, with my wife and
2 children (both under 2). I was shocked when I went to change my
10-week old daughter’s nappy, only to be told that there were no baby
changing facilities on board.

It was odd that there were symbols on the toilet doors indicating baby
changing facilities but no such facilities inside. The conductor told
me that FGW had taken them out. I find this utterly incredible.

I had to change my daughter on the dirty floor at the end of a
carriage. The conductor was extremely helpful in the circumstances and
made sure no-one came passed (and gave us £5 for refreshments), but it
was pretty disgraceful I had to do it at all.

It is very family unfriendly and unhygienic, and the decision to take them
OUT seems even more unbelievable. I would love to know the rationale
for this decision.


I guess I can just be thankful my 22-month old son didn’t have a dirty nappy, then they might have had a few more complaints.

P.S. I did tweet @FGW and had this unenlightening exchange:

[View the story “Baby changing facilities on FGW trains” on Storify]

How to engage a baby

When you share a laugh with your baby, it can be one the warmest feelings as a parent. But is this a genuine mutual exchange, and how does it come about?

This is a video of what is now a classic experiment in developmental psychology. It shows a mother happily engaging face-to-face with an equally happy baby. The mother then ceases all facial engagement – the “still face” – to which the baby reacts by trying, with all its might, to reestablish the happy interactions. It’s quite a marked and powerful effect:

A historical review of the experiment quotes the researchers who first documented the effect:

“the infant first “orients toward the mother” and “greets her expectantly.” But then, when the mother “fails to respond appropriately,” the infant …

… rapidly sobers and grows wary. He makes repeated attempts to get the interaction into its usual reciprocal pattern. When these attempts fail, the infant withdraws [and] orients his face and body away from his mother with a withdrawn, hopeless facial expression.”

The experiment, in this form, was first presented at a scientific conference in 1975, but it wasn’t the first to document what happened when infants are exposed to varying social interactions. It was, however, the first to use “then-novel videotape technology” on the conference hall’s big screen. Adamson and Frick, in their historical review, suggest that the  immediate and dramatic illustration of the phenomenon contributed to the broad interest this experiment gained. An early lesson in the power of ‘modern’ technology for effective science communication and to maximise research impact.

This may all seem a little obvious to some parents. You may feel that you don’t need a psychologist with a video camera to tell you that a baby is happiest when you are engaging them face-to-face. But there are a number of reasons why the methodical description of this effect has had profound and lasting influence.  

What this experiment first showed, by deliberately manipulating the parent’s engagement, was that the baby is an active player in this exchange. The infant’s social behaviours can influence the parent’s level of engagement, just as the parent can influence the baby, and it can subtly alter these depending on the context. It’s not simply the parent reacting to the baby’s randomly generated cues. It has even been detected in babies as young as a few weeks old.

As Jason Goldman at The Thoughtful Animal says:

“The still face experiment demonstrated that very young infants already have several basic building blocks of social cognition in place. It suggested that they have some sense of the relationship between facial expression and emotion, that they have some primitive social understanding, and that they are able to regulate their own affect and attention to some extent. The infants’ attempts to re-engage with their caregivers also suggest that they are able to plan and execute simple goal-directed behaviors.”

But one reason why this experiment has been so important and enduring is that it provided a standard and reproducible way of measuring children’s social emotional development.

By using the same set-up time-and-time again, it has shown how a child’s social and emotional development becomes richer as they grow older. The response becomes increasingly complex with age, and can include deftly timed facial cues, dampened smiles, sideways glances at their parent and yawns. Adamson and Frick cite a lovely example for the original set of experiments in which a five-month old boy, upon encountering a still face, stopped being wary and…

“…looked at the mother and laughed briefly. After this brief tense laugh, he paused, looked at her soberly, and then laughed again, loud and long, throwing his head back as he did so. At this point, the mother became unable to maintain an unresponsive still face.”

An experience I’m sure many a parent can relate to when – armed with a stern face – they try earnestly to tell off their child, only to be met with a cheeky grin or giggle!

The experiment has also allowed researchers to deconstruct these parent-baby social interactions into visual, auditory and tactile components. Vision and hearing, it seems, is especially important as children get older, but touch can be enough to, at least partially, lessen an infant’s anxiety when confronted with a still face.

Nevertheless, a still face is usually enough to produce the basic negative reaction in a child, even if it’s in response to their mother, father, a stranger or someone on television. Children make a distinction, however, for inanimate objects, even if they appear quite human-like, demonstrating their ability to form genuine social relationships.

This experimental set-up has also revealed possible negative consequences of a parent’s still face. According to Adamson and Frick, children actually show a more dramatic reaction to a still face than to a brief period of separation or to situations in which the parent interrupts interactions to talk to a researcher. Babies assimilate and react to a negative social cue, rather than simply becoming distressed at the lack of stimulation.

The “still face” experiment has shown its use in further understanding various developmental disorders, such as Down’s syndrome, deafness and autism, as well the effects of environmental conditions like infants exposed to cocaine prenatally or to depressed mothers.

The still face experiment has been used to ask questions about how early social and emotional engagement may affect later behaviour. The strength of an infant’s still face effect has been linked to their mother’s normal sensitivity and interactive style, and it may predict the degree of later infant attachment, depression or anxiety, and even behavioural problems.

Clearly, parents who may have a lower level of engagement, such as those experiencing postpartum depression, should not be guilt-tripped, especially as this could have an exacerbating effect. But the still face experiment has shown that simple procedures can help in these situations – depressed mothers who are encouraged to provide more touch stimulation are often able to offset the lack of visual or auditory engagement to bring about more positive social interations.

As Ed Tronick – one of the original researchers of the “still face” experiment – says on his website:

“An infant’s exposure to “good, bad, and ugly” interactions with the mother, as repeatedly communicated by her facial expressions or lack of expression (i.e., a still-face) has long-term consequences for the infant’s confidence and curiosity, or social emotional development, with which to experience and engage the world.

Though let’s not forget the role of fathers, or other partners, either.

[Thanks to mum-in-law Jenny (once again) for the video and @matthewcobb for the Adamson and Frick article]