Similarly , animals tend to consume less of an item as the cost of that item increases ( e.g. more lever presses required ) .
Humans usually decrease the amount of an item purchased ( or consumed ) as the cost of that item increases .
Animals tend to consume less of an item as the cost of that item increases ( e.g. more lever presses required ) .
Humans usually decrease the amount of an item purchased ( or consumed ) as the cost of that item increases .