Setting environment path for system.callSystem()?

I'm running macOS Sierra.

In my ExtendScript code I have:

system.callSystem("echo $PATH");

This results in the following output in the ESTK's Javascript Console:

/usr/bin:/bin:/usr/sbin:/sbin

However, if I enter the same command directly in a terminal window, like so:

echo $PATH

The following is output:

/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin

So it seems that ExtendScript operates in a different environment than the one my user has?  I'm not understanding why the $PATH variable is showing differently in the two different contexts.  The documentation for system.callSystem state:

Executes a system command, as if you had typed it on the operating system’s command line. Returns whatever the system outputs in response to the command, if anything.

Is there anything I can do ensure that the system.callSystem method makes use of my current environment path?

Thanks!