Are your pigs regressive or progressive?

BBC’s Countryfile recently showed research being done to find out whether pigs were regressive or progressive.
They put individual pigs into a confined space with an object in it, to see whether the object was approached quickly, slowly or not at all.
Each pig was identified and their progress monitored to see how much more or less feed each category of pig took and the effect on their subsequent growth rate and FCR. It showed that the progressive (nosy) pig ate more and grew faster than the regressive (shy) pig.
I suppose, unbeknown to us mere mortals, all kinds of work is going on for the most obscure of reasons and all hopefully with some sort of advantage for the future of our pig industry.
If progressive behavior can be bred into genetics, can you imagine the boost that would give to breeding companies? They could encourage farmers to ‘use our progressive genetics, save feed and have faster growth’.
I do wonder how much of it could be genetic, rather than how a pig might feel on any particular day? After all, whether we humans are either progressive or regressive can vary on precisely how we feel, whether or not a hangover is involved!
Genetics are a fascinating subject and have improved our breeding stock manifold times. We have learned how to feed our sows during pregnancy to obtain sufficiently viable piglets at birth, how to feed them during suckling and how to keep sows in good condition for the next serving.
It was easy in the olden days when 10 or less were being suckled but as sow body length increased, which in turn lengthened the womb, we now have many litters of late-teen numbers born.
The problem that brings is the viability of the smaller piglets. In round figures, it is accepted that a pig at weaning which is one kilo lighter than another, will take an extra week to finish, worth around another £5 in feed. So if a pig is lighter at birth, its is likely to be lighter at weaning.
The new genetics we now have produce more teats – I saw some recently where the gilts had 18 functional teats.
That means that a large number born can be suckled more easily. But if there are 18 piglets, will they all be the same size, will they all stick to the same teats, or will the largest and most vigorous always grab the front teats?
The Chinese Meishan is famed for having huge litters but they are more or less the same size and take longer to mature.
Someone told me China still has 40 per cent of the global pigs, but 80 per cent of those are still the old, fat, slow growing type. If they were improved to eat efficiently, there would be 12 per cent less demand globally for wheat and soya.
And here am I thinking cereal prices are too low now!