Do they bollocks! The lids require some strength to open, but no more that could be exerted by an enraged four-year-old, after aligning little arrows or knobs or marks, leaning and twisting in the correct order and so on. Any half-way bored child will simply lean, twist, turn, shove and pull in all combinations until the thing is opened. Richard amazed my father by finding his way past child-proof locks at the age of three, simply by trying everything. That is why children are better with video recorders, computer games than adults are. They have lots of time, and they are not afraid of breaking it.
(This is not just my assertion - a video equipment manufacturer studied this early in 2001, reporting just this conclusion on the news. They had hoped that children had the secret of easier-to-operate equipment. Well, they do: it is to have lots of time and a conviction that, if you break it, Daddy will pay for a repair.)
The people who cannot get into child-proof bottles of aspirin are people with arthritis, whose fingers cannot grip the cap. Or someone with a blinding headache who cannot see with the instructions or the tiny little arrows they are meant to line up before pushing on the opposite side of the lid. Bloody hell, I thought one day in August, enraged by one of these inventions of Satan and a rather severe hangover, these are actually patient-proof medicines.
After I had chewed my way through the base of the bottle and got enough aspirin to think rationally, I wondered what a child-proof bottle would actually be like.
A hugely tight cap is the obvious one, but this assumes that you use a pipe wrench to put the top back on as well as take it off, unless you postulate motorised bottle tops. Anyway, many 10-year-olds are as strong as some adults. And it still does not allow the arthritic to get in.
More complicated caps might seem attractive. Rather than 'lean and push' or 'align arrows and flip', you could have 'align country (on cap) with capital city (on bottle)' or 'point arrow on bottle to the number which is its exact square on the cap' or 'rotate, push, pull, flip and turn in alphabetical order'. But this would still fall prey to the 'try everything at random' approach, and many adults would be incapable of following the instructions.
No, neither strength nor intelligence are the answer. You want something that is genuinely unique to adults,. There are two options.
The first is a sex hormone-sensitive lid. Such bottles would explode open whenever teenage boys walked by, while the post-menopausal would find themselves denied all medical help. But it would do for young family use. However that requires a lot of sensor and motor power in the cap, and would probably cost more to develop than the medicines inside the bottle.
No, I prefer money. The one thing that adults have and juveniles do not is economic power, so you make a cap which only opens if you put a £10 note in, which it then keeps. Every aspirin therefore costs you £10 in hard cash. When the bottle of 50 is empty, you send it off to Glaxo, who send you back a refilled bottle and a £495 cheque.
You have to set the price at the right level, of course, as otherwise a teenager wanting relief from their headache will find it cheaper to buy street heroin instead, with unfortunate effects.
I can think of nothing wrong with this scheme, except the possibility of a sudden rise in un-drug related crime, with impoverished youths stealing empty drug bottles for the money.