People have been สล็อตออนไลน์ shaking hands to show friendship and trust since the days of Ancient Greece and Medieval Europe.
But does the fact centuries-old habits like this have had to change during the coronavirus pandemic give us an insight into why social distancing and lockdown rules are sometimes broken?
Public attitudes expert Dr Simon Williams believes so - and he thinks the effects of lifestyle changes since the outbreak could be felt by people for up to three years after the pandemic.
For psychologist Prof Fay Short, there are three kinds of rule-breakers - people who don't understand the Covid-19 rules, people who don't think they are important, and those who are trying to exert control.
As Wales begins a two-week "firebreak" lockdown, BBC Wales took a look at what lies behind people's inability to stick to some of the pandemic guidance so far.
"One of the concerns that people voiced during the first lockdown was that they would find it hard to go in and out of lockdown," said Dr Williams of Swansea University.
"This is now the reality."
While adherence to rules during the first lockdown was "extremely high", he said, there were now "a growing number of divisions in society", following a number of local lockdowns and the launch of the second national lockdown on Friday evening.