Just a simple test today with bonding.
I have a new Jell/Plant spawned from the book with Not Serious, Temperment and Amathyst, Favorite. Of course it has no bonding but needs to build it quickly to keep from panicking in battles. I tried training the first month of its life a couple differant ways (reseting after each of course):
In all the tests a Melon was fed on wk3

rest, rest, rest, rest = 0 bonding
Of course, this is just like the lifespan tests, bonding will never increase if the monster just rests.

lvl2, lvl2, lvl2, rest = smallest sliver of bonding

lvl1, lvl1, lvl1, lvl1 = about 1/3 length of focus arrow of bonding

Clearly more bonding developed from lvl1 training (shadow boxing) than from lvl2 trainig (target)
So I tried a few variants of the lvl1 training:

With eight praises per week = about 1/2 length of focus arrow of bonding

With eight scolds per week = smallest sliver of bonding

With praising until policy easy, then scold, then more praising until policy easy... = about 1/2 length of focus arrow of bonding
(about 3 praises per 1 scold, works out to 23 praises and 8 scolds in one month)

With one Amathyst per week = smallest sliver of bonding
I am amazed that giving the Jell its favorite item every week resulted in less bonding than letting it do lvl1 drills with out any interaction.

I used a piece of paper held against the screen to record the final sizes of the bonding bar (silly but consistant). There isn't any doubt for me that praising and light drills resulted in more bonding in less time. Half an arrow versus practically none is easy enough to see even with the naked eye.

Back in MR1 & MR2 (I never played MR3) keeping the monster neutral was crutial to building loyalty. I'm not sure that is the case in MR4.

I will try this test with a Serious monster for comparison but praising and low difficulty drills can have a huge impact on the rate bonding builds.

EDIT: lvl1 training alone won't result in 1/3 length of focus arrow of bonding in only one month. There was a typo in my notes.

I tried the test with five other Jell/Plants with temperments:
Cheerful, Not Serious, Timid, Spoiled, Brave

All three developed the same amount of bonding using: lvl1, lvl1, lvl1, lv1 and no interferance. Although the Cheerful one became frustrated on wk4.

Honestly I was expecting simpler results or some sort of break through. I will have to rethink the tests design this so there is only one variable.

It really depends on their mood. If you use the same training gadget with a cheerful or not serious they may get frustrated and lose bonding. I found that most Not Serious monsters like it when you rotate them from training gadgets. The bonding part depends on how you train them. I had a few "Not Serious" monsters and tried different training styles. If you train them constantly in the same thing it dosen't raise the bonding level much. If you rotate them between 2 different gadgets their training level will increase and bonding goes up more than just putting them on a trampoline. If you select gadgets at random their training will be worse and the bonding goes up at about what the rotating did. The gadgets make them tired so if you keep using them repeatedly the monster will get tired and frustrated. If you use the lvl1 type of training they won't get as tired and they will like you more.

Still working on this.