Based on discussions with friends and colleagues there seem to be difficulties opening child-resistant packages in general. There are even stories of parents letting their kids (supervised) open child resistant-packages just because they couldn't open the package themselves.

This is not the intention of Medicines and Healthcare products Regulatory Agency which on the topic of Child resistant packaging:

Child resistant packaging is a useful deterrent in preventing accidental poisoning of young children. However, it is intended to be a last line of defence with safe and appropriate storage of medicines being the primary preventative measure in harm reduction.

A child resistant package is a package which is difficult for young children to open (or gain access to the contents) but which is not difficult for adults to use properly.

I guess that there is a difference between what authority intended and the outcome. The difficulty opening child resistant packages is also mentioned in the Wikipedia article Child-resistant packaging:

Child-resistant packaging can be a problem for some aged individuals or people with disabilities. Regulations require designs to be tested to verify that most adults can access the package. Some jurisdictions allow pharmacists to provide medications in non C-R packages when there are no children in the same house.

Which makes me wonder Why are child-resistant packages sometimes easier to open by kids than adults?

  • 1
    Probably not exactly what you wanted but this is interesting: epa.gov/PR_Notices/pr96-2.html Crucial to note that the "Child" cohort is " 42-51 months old " i.e. No one older than 5 years of age. Mar 17, 2013 at 9:50
  • Because children have small fingers ? Mar 17, 2013 at 10:02
  • 1
    @NicolasBarbulesco: Small need not equate dexterous. Mar 17, 2013 at 13:16
  • 1
    Often such packaging requires pressure - which may be more easily applied by relatively small hands.
    – penguat
    Mar 20, 2013 at 14:31
  • 1
    I think the key here is that they are easier to open by some kids, and by some adults. I've never seen one that I can't open, but plenty that are girlfriend proof :)
    – JohnGB
    May 1, 2013 at 17:01

12 Answers 12


I found this link which might help you to answer why kids perform better than adults sometimes. Hope the big article helps to some extent :) This is a part of discussion between two experts and the interviewer.

Just an excerpt from the same page:

TKF: My daughter and I are learning the pedal harp, and I find I progress much slower than she does. She started harp lessons at the same time as me, but at the age of 11. Why is she learning at a faster rate than me?

MICHAEL MERZENICH: I have done several studies to try to understand why adults are frustrated by what they are trying to accomplish, and it almost always comes back to the influences of their earlier neurological histories, and the platform from which their brains are operating given those histories. For example, it is probable that in your practice on the harp, you did not go back to the most elemental stages of learning, unlike your daughter. You likely initiated work on the instrument based on a platform of your other musical experiences, and have done a poorer job than your daughter of establishing all of the elementary skills or abilities that support proficient musicianship. Your daughter’s brain began closer to the beginning. It has probably done a much more complete job of modifying itself to more fully master the elemental abilities that more strongly support highest level abilities.

TKF: But I do the same basic practice exercises that she does.

MICHAEL MERZENICH: More practice may not help without going back to the beginning and going through the full set of skills and refining them progressively in the right order. You may lack elemental skills related to the control of movement or some aspects of listening that won’t improve simply by repetitively plucking the harp strings. For example, most people that have trouble remembering, think they can improve their memory just by practicing remembering. But there are a lot of basic skills that underlie a good memory, such as listening skills, that may need practice instead.

TKF: Studies suggest that many of our mental abilities decline as we enter our elder years. What’s the brain explanation for that?

RANDY NUDO: There’s a loss of synaptic connections that increases with age and virtually everything that makes us who we are is encoded in those synapses—when we learn something or hold on to a memory, it’s encoded across many different synapses. Synaptic loss occurs differentially in different brain areas and is subject to different environmental influences. You will see behavioral evidence first in those structures that require the most computational power. That might explain the loss of memory seen in older people, even in those who don’t have some disorder like Alzheimer’s disease.

  • 1
    +1 Thanks for the link! This was exactly what I was looking for. Great reference! Mar 22, 2013 at 7:22
  • Empirically I've observed that the ability to memorise 'new information' drops off rather alarmingly between the teenage years and the 'elder years' which seem to start around the mid 30s / early 40s.
    – PhillipW
    Mar 29, 2013 at 9:57
  • 1
    I don't see how this relates to child resistant packaging. Child-resistant packaging usually relies on hand dexterity that very young children may not have developed; the linked article seems to be more about mental/motor learning instead of dexterity.
    – Lie Ryan
    Apr 25, 2013 at 8:00

Because kids still have a sense of exploring their world and will try things because they aren't sure how things work. So when something doesn't work, they will try a different way. Children tend to be more creative than adults as they are less constrained by experience.

Older adults have years of life confirming that things should be done in a particular way, so they typically explore less. So they are sure how things work - even when they are wrong. Hence when something doesn't work the way they expect, they don't think laterally and try other ways that haven't worked in the past.

A good reference book on creativity is The Creative Spirit by Dan Goleman, Paul Kaufman, and Michael Ray.


For starters, the definition of child resistant packaging states:

To be child-resistant, 85% of tested children less than 5 years old must not be able to open the package within 5 minutes (this means 15% of children can open the package quickly), and 90% of tested adults must be able to open and properly close the package within 5 minutes.

I found a few studies stating the decrease in the number of accidental ingestion of drugs by children declined, but did not end, with the use of child resistant packaging. http://www.pharmacytimes.com/publications/issue/2007/2007-05/2007-05-6518 http://archpedi.jamanetwork.com/article.aspx?articleid=203811

My 0.02$ on the matter:

The main theme in all the articles I came across was quite clear, Child resistant is not child proof. Children, one way or another, learn how to open the bottles. Now, the explanation behind how they do this has not been studied per se, but I would speculate that, given enough time with it and unless the container itself breaks, or the child looses interest in it, sooner or later the child will figure out how to open it. Curiosity is an inborn trait in humans, we want to explore everything we see, whether it is electric sockets, or a stove or a package. Part of the curiosity is know what it is with the use of the 5 senses (sight, smell, touch, taste, sound). Those are the same medium which we use to attract the child's attention. For how they do it, we need to look into the products you are talking about. If we imagine the 'press and twist' bottle caps which we find in some of these child resistant products. The child has seen enough examples of opening bottles by twisting the head to get what's inside (we have enough jars in the kitchen). Now by trial and error, it is quite easy that the child presses the soft region and twists it. Viola, impending doom!

All "new" packaging design is derived in some way or another, from an existing mechanism. As an adult one might not be "creative" enough to figure it out quick enough. But a child is not bent into thinking in a particular fashion by years or training/conditioning/what-have-you, it does not mind experimenting. If the experiment works, it works, else it just forgets the thing and moves on.

  • +1 for surprisingly correct usage of "it" and the strangeness of gender neutral pronouns in English.
    – Max DeLiso
    Mar 20, 2013 at 14:53
  • This made me realize that the best way to achieve a child-resistant packaging is to have a two-layer strategy. Removing the outer CR proof cap would open the outer compartment containing e.g. child-safe sweets (avoid choke hazards!) as well as allowing access to the inner cap. The curious kid who does manage to open the outer cap would have its curiosity rewarded, and hopefully be distracted enough to ignore the second cap. This especially works around copying behavior: the kid sees the parent open the container, take out something, and close it again.
    – MSalters
    Feb 18, 2015 at 16:09
  • 1
    No sane adult will spend 5 minutes getting a pill bottle open. They could have walked next door and asked a neighbor to open it by then. Now, metal food cans in the wilderness without a can opener is another story... (a long and boring one)
    – user67695
    Jun 14, 2017 at 14:54

As you have stated, it is never the intention of these packaging requirements to make the packaging easier for children to open than adults. In fact any packaging that cannot be opened by 90% of seniors (aged 50–70) fail the packaging tests themselves (16 CFR § 1700.20).

The test for seniors—16 CFR § 1700.20(a)(3)—requires the following:

  • 100 senior adults, divided into age groups (25% 50–54 years, 25% 55–59 years, 50% 60–70 years), and with no more than 24% of the tests performed at the one site.
  • No individual tester may test more than 35% of the adults tested
  • None of the adults tested should have any obvious or overt physical or mental disability

The test itself is quite simple; if the adult can't open the test packaging in 5 minutes, they're given two "conventional" packages (not child-resistant). If they can't open and close both of those control packages in a minute they are removed from the pool of test participants. The whole test is considered a success if 90% of the test participants were able to open the packaging within 5 minutes (and the remaining 10% weren't otherwise removed from the testing pool).

In terms of the test for restricting children—16 CFR § 1700.20(a)(2)—the test is equally simple:

  • 1–4 groups of 50 children, randomly selected and divided into age groups (30% aged 42–44 months, 40% aged 45–48 months and 30% aged 49–51 months), with relatively balanced gender distribution and with no more than 20% tests performed at the one site.
  • No individual tester may test more than 30% of the children tested
  • None of the children tested should have any obvious or overt physical or mental handicap.
  • If, after 5 minutes, the child hasn't tried to use their teeth to open the packaging, they are explicitly instructed to try.

The test is recorded as a failure if the child opens the packaging or otherwise gains access to the contents within the 10 minute test. The test as a whole is treated as a failure if more than 20% of the children tested (after 4 groups) can open the package. It has a complex sequential test in place to direct testers when they need to increase the number of groups tested.

Here's a fairly simple summary of the test.

In general, it's impossible for every piece of packaging to be able to be opened by every adult. As people age and develop motor control disabilities and other similar handicaps, they can lose even the ability to open the simpler/non-CR packaging.

Children (of a certain age) are—given infinite time—able to open pretty much anything. They can use tools to destroy the packaging, they can give the packaging to the dog to try to chew open, whatever the case may be.

It is therefore unfortunately true that CR packages are sometimes "easier" to open by kids than adults, no matter the design of the CR packages.

You state in your question:

I guess that there is a difference between what authority intended and the outcome.

In the general case—which is all that is testable—it is clearly intended for packaging to be profoundly easier to open as an adult than as a child. I believe it is not only the authority's intent, but their provable outcome that the packaging is "difficult for young children to open (or gain access to the contents) but which is not difficult for adults to use properly".

It is simply an unfortunate fact of life that there will always be edge cases that are not representative of the entire group (in this case, adults—even seniors).

  • 4
    +1 for a detailed outline of the testing procedure. Child-resistant packaging is probably a misnomer, it really should be called infant-resistant packaging. Children around 8-10 years old generally have enough sensibility to follow instruction when an adult told them that the medicine is not for them. The only time a child at that age might open the bottle AND consume and overdose on it is probably if the child is suicidal, then you have a BIGGER problem than child-resistant packaging.
    – Lie Ryan
    Apr 25, 2013 at 8:41
  • 5 minutes? No adult will spend more than 5 seconds trying to open a package unassisted. We have better things to do.
    – user67695
    Jun 14, 2017 at 14:57

A lot of this depends on the framing: i.e. "What age are children supposed to be deterred most by the packaging?"

I bet the cases mentioned of "parents letting their kids (supervised) open child resistant-packages" do not refer to 4-year olds, but more likely 8-year-old-plus kids.

At the extreme if you use a quasi-legal definition of "children" as

"A young human being below the age of full physical development or below the legal age of majority."

you'd be including 16 and 17 year olds. At that age it'd be no mystery that they would be able to open the packaging as well or even better than their parents.

My point is the usage cases supposed to be detered by child resistant packaging IMHO are children between, say, 2 and 6 years of age. These might be most likely to go around accidentally exploring and ingest medicine as candy etc.

The fact that the, say, 8-16 year cohort proves to be more adept at opening these locks than even adults does not detract from the effectiveness of the basic design.


"Sometimes easier to open" may man one of these:

  • there are some child-resistant packages that are easier to open by children
  • there are some chilren that find opening child-resistant packages easier than adults
  • there are some reports of children opening the child-resistant packages easier than adults

This division is important, because each of the three means something else:

  • The first one focuses on the object. Being able to say that a package is easier to open by a child than by an adult person is something behind statistics and can be considered as a rule. Thus, while constructed with intention not to be easily opened by children, the construction of these packages is obviously a failure.
  • The second one focuses on the child. It still allows to form a rule about a package being more easily opened by a child but only if this child has some over-average abilities (like strength, manipulating or intelectual skills), so this rule would apply only to a selected group of children.
  • The third one is random. It says that there are situations like this, however no specific regularity can be assigned to them. I mean, it’s a lack of such regularity, not insufficient data collected, allowing to assign these situations to one of the former groups. In the same time, the scale cannot be too high, because having it at high level would automatically make it fall into the first group.

Now, it’s hard to analyze randomness, but it is possible to focus on the child and object. Let’s start from the child-point-of-view approach. First of all, child is a user; in fact, there are two types of users of a child-resistant package:

  • adult (the intended user)
  • child (the unintended user)

The tricky part is to make the package accessible for the intended user while keeping it totally inaccessible for the unintended user. It is a very difficult task because of these factors:

  • within the population of adults, the skill set can vary (namely: it can be lower than average)
  • within the population of children, the skill set can vary as well (namely: it can be higher than average)

These two factors make it necessary to increase accessibility of a child-resistant package (to make it possible to open for a "weak adult”) while decreasing its accessibility in the same time (to make it impossible to open for a „strong child”). These two are quite contradictory, however, it is still possible to find some ways of securing a package in such a way that would make it less possible for children to open it while keeping it still quite easy to open for an adult. This is actually the idea behind child-resistant packaging anyway. The skills that are mostly considered in this case are a combination of strenght, manipulation skills, knowledge and intelectual skills):

  • strength and manipulating skills, as requirements to open the package, are necessary to push the nut and unscrew it while pushed
  • knowledge and intelectual skills are in the same time necessary to be aware of the way of opening the package. It is very important that usually a child simply cannot gain this knowledge by trial and error - it will fail on the strength and manipulating skills requirement, so no success for a series of such trials is possible (again: usually). However, this knowledge can be gained from observing an adult or a child might develop this idea itself. (And sometimes no experience at all is the biggest advantage of the ideating process!)

If any of these requirements is fulflled, completing the other ones becomes simple. If a child has great strength - it will easily open the package after some trial and error game. If it has knowledge - sooner or later he or she will find maybe enough strength, or use a tool, to open it. A bare idea has some question mark somewhere, but it leads to the same result in the end. As in fact it ie easy to guess or gain a knowledge about opening a child-resistant package, the real limitation should be put in strength requirement.

One more very important thing is that children are a very broad category of users, no matter if these are intended or unintended user. This means only that within the group the skill set is very different, based on factors such as age, environment, innate skills, development etc. In the same time, the intended users of a vial of medicine can be - in many cases - persons with limited strangth, older people with limited intelectual skills („I don’t know how to open it, sweetie.” „I will help you, grandma.”). So we are back to skill set overlapping. In big population, there is no way to avoid it to overlap, and thus there is no way to avoid situations in which children are able to open such packagings.

However, it is not opening child-resistant packages that is a source of the problem (or rather: a threat) of children overdosing a medicine. Not always this skill leads to such consequences. With age, children usually gain more strength, knowledge and they develop their manipulating and intelectual skills. In the same time, they develop also a sense of responsibility and consequence. Both of these developments are though paralell, and it is very probable, that a child will have enough sense of consequence when it develops skills for opening such a package.

This topic could be easily extended to more areas (such as electric socket blockers, door and drawer locks etc.) but I think that it all falls into the same scheme at this level of generalizing.


Worth researching the term divergent thinking which is especially applicable to children and which as we age, we loose the ability to do for a variety of reasons... This may partly explain your question/hypothesis...

There is a remarkable talk by Sir Ken Robinson on changing educational paradigms at the RSA in London, which includes references to divergent thinking in children, which you can find here.

He also published a book on the subject which can be found here on Amazon.


Few thoughts

  • The one who doesn't know tries every way but the one who knows tries one from his known ways.

  • Also there is a gap in the attention when you know you could do and when you have to figure out first how to do. Sometimes "I know how to do" attitude acts as barrier and stops your learning process altogether.

  • I have personally experienced such situation in which while editing a Joomla template code, I "kind of knew" where this control would be but since version had changed and things were done differently in new version, I kept digging the wrong section for hours with wrong approach. Ultimately I had to browse through "FORUMS" to find the answer and I discovered the new approach was rather straight forward but I never never put my mind into "Learn" mode to notice that.

  • With age, we also tend go get less patient and less tolerant to failures. With age with also develop a mindset "I cannot do this anymore" and this idea acts as venom destroys problem solving potentials. If we cannot do it for few minutes, we switch over to "I cannot do this anymore" approach and from that mindset, there is usually no way back but a desire to seek help.

  • Another factor which acts on our thinking is that "I have helpers around". When we are young, we are the helpers ourselves and when we grow old, our children and family become our helpers. So idea of having somebody who can do it makes us quit trying sooner.

  • Another minor but contributing factor is our weakening muscles. Internally we know we have applied enough force but factually a lot less is exerted by the weakened muscles. So even if we were on the right track, we kind of think this was not the way.

My points are not specific to "opening the bottle of medicine" alone and the same would hold true for several similar situations.

  • Good points. It is now possible in the US to request "adult friendly" pill bottles when getting medicine from a pharmacy. But the usual "push really hard and twist" is the only pill mechanism I can recall seeing. This is nearly universal for bottles of liquid dangerous substances also (cleaners, auto chemicals etc). I have trouble imagining another type of cap that would be functional.
    – user67695
    Jun 14, 2017 at 15:01

I wouldn't underplay the actual physical problems that older adults have.

Many adults in their mid to late 40s won't actually be able to see 'small stuff' properly as their close sight starts to fail without glasses - and there is a natural tendency for adults to resist getting (and wearing) glasses which fix this problem.

  • Often their distance vision fails as well. Sometimes, vision starts to fail entirely. Along with hearing, touch sensitivity, smell, taste... Eventually they just don't do anything! :)
    – user67695
    Jun 14, 2017 at 15:07

Kids are naturally good at interpreting a sequence their very own way to achieve a personal -or given- goal. They also seem to not care about the potential consequences such as falling, spilling or breaking the fragile part, etc.

Focusing on the primary goal allow them to be more creative when solving problems: apply more strength, putting things upside down, smashing things, etc. Whereas adults are better -but not always!- at evaluating the side effects of a particular method.

  • Famous quote: "Good judgement comes from experience. Experience comes from bad judgement."
    – user67695
    Jun 14, 2017 at 15:04

Because kids have far more flexible minds than adults.

As you grow, your thinking is literally put on rails. The approaches you use to solve problems rely on the tried and true. This also means that you are far more likely to give up when you come across a problem where the standard approaches don't work.

Children, on the other hand, have to learn by necessity because they are still discovering the world they live in and their brain excels at it. They will try an approach even if it doesn't make sense initially. This greatly increases their chances of success with unusual problems, for example, child-resistant packaging.


Child resistant packages are not more easily opened by the people that they are truly trying to keep out -- for example, five year-olds and younger.

You only asked this question because you had this: "There are even stories of parents letting their kids (supervised) open child resistant-packages just because they couldn't open the package themselves" Well, "there are even stories of..." does not make it a true phenomenon. In fact, I think that "child-proof packages are more easily opened by kids" is in fact a sort of corny old joke that gets repeated by Andy Rooney and people around the water cooler, and is not actually true. Child proof packages do keep out kids, and the result likely saves many lives. Do I have proof? No. But before we spend time trying to answer your thesis, we would first want to ask if it was at all true... I don't think it is.

  • You can ask for medicines from a pharmacy in ordinary packages, so that suggests to me that some adults do indeed have trouble opening the "resistant" ones. Basically, the package requires a level of strength and dexterity that not everyone has. Some of these are children, some are adults. It was the worst solution to the problem, except for all the other solutions that were tried.
    – user67695
    Jun 14, 2017 at 15:09

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