Here’s your object lesson for modern times.
When I was doing this kind of operant-conditioning with rats at Emory U., I had 3 rats.
One rat, when pressing the lever, never got rewarded with food. Another rat always got food when pressing the lever.
The third rat would never know when he got rewarded. He was intermittently being rewarded.
According to behavioralist B.F.Skinner, the intermittently rewarded rat should press the lever most often. This rat would have to work harder to get his food -never knowing when depressing the lever would bring him a bite to eat.
My rat disproved Skinnerian behavioralism, but portended present times. My rat winner ( the one pressing the lever most often ) was the rat who got rewarded every time.
Not much different from the Demo-rats who line up for Obama-money. All are risque averse. Just line up, take a number and get your treat.
Skinner was a bit of a nut. He even put his own kid in a Skinner box for experimental purposes.
So that’s why Dad had me press that lever after I mowed the lawn.