DNS vs /etc/hosts

[Lowell.Hought@xxxxxxx]

I am changing from 7.2 to 8.0 and have
both installed now on various Linux machines.  When I use the psql
command line interface with a -h hostname, the connection time from 7.2
is instant while the connection time from 8.0 is 15 seconds.  My assumption
is that 7.2 checks the /etc/hosts file first and if unable to find the
specified host it reverts to a DNS lookup, and the 8.0 is just the opposite.
 Is this a correct assumption, and if so, can I modify 8.0 to behave
as 7.2 does?