It is agreed that not all examples of exchange are 'trade', by which I take
it is meant that they are 'monetised'.  This is Polanyi's point in the
extreme, which I find problematic.

Adam Smith did not use 'trade' in his famous example of the 'butcher,
brewer, and baker' In Wealth Of Nations.  He emphatically used the word
'exchange'.  It was the human propensity to exchange that he emphasised and
he placed it well back into human history ('reason' and speech').

In exchange we have 'an activity in which both parties are aware of a mutual
advantage', which is a wider event in human relations than monetised trade. 

'If monkeys groom each other that might be trade if each paid the other $5'.

Assuming we may extend 'monkeys' to primates like apes, where the research I
quoted from Robin Dunbar (in his 'Gossip' book) was focussed, this was not
just sociability.  All apes groom, when commanded, by the alpha male and
applies to other subordinates in the hierarchies, male and female, who also
groom when commanded.  That is 'sociability'.  

But Dunbar's team noted 'discretionary grooming' sets in which pairs would
regularly groom each other in reciprocal exchanges and would also refuse to
groom certain others.  Grooming takes over an hour and has high benefits for
the groomed. There are only so many hours in the daylight. So apart from
obligatory grooming by command, they choose to spend scarce time in a day to
groom others by discretion and receive grooming from those specific others.

That is an exchange relationship based on reciprocity: 'You scratch my back
and I'll scratch yours' (!), or the implicit conditional proposition: 'If
you groom me, I shall groom you' - otherwise I won't.'  I call this the
quasi-bargain in that it is unenforceable, implicit and the condition and
the offer are separated in time, in contrast to the Smithian conditional
'bargain': 'Give me that which I want, and you shall have this which you
want' (WN I.ii.2: p 26), in which the transaction is immediate, not delayed
and concluded.

It is not in the intention to reciprocate, nor always in the expectation,
that the quasi-bargain is completed (one or other must undertake a grooming
session first), but the consequences of non-reciprocation later, perhaps
days or weeks later, is where the sanctions of no further exchanges occur.
Dunbar reports that discretionary grooming is stable between pairs,
sometimes several pairs in a grooming 'network'.

No $5 charge is made, of course.  But the exchange transaction is the
currency of the trade.  Christmas gifts, like all gifts in early societies,
are exchanges, but not necessarily monetary exchanges, except it is known
that the relative worth of the gifts in many cases are important to the
parties (and formally so in Japanese gift exchanges).

There are advantages in looking beyond purely monetary exchanges, especially
when we look at the evolution of exchange in human societies.  Exchanges are
not always cost-free and their relative worth is not necessarily
articulated.  But without the habit-forming exchange behaviour (the
quasi-bargain) over a long period of time (money is a relatively recent
evolved invention), it is doubtful if the long process of the propensity to
exchange would have developed ab initio or, dare I say, 'spontaneously'. 

Gavin Kennedy