1- a team not doing tdd have training about solid principles and the demeter law, than the team is requested to produce code that conform to these principles

2- instead the same team have training about tdd with mock objects: about the practices and smells prescribed by the practice and the refacorings to remove duplications and clarify code intent. than the team is requested to write code driven by tdd with mock objects

in the example -1- the learning and application of the principles is non-automatic: say it is intentional.
in my experience i have observed many devs and 1 team succeeding into learning the principles and still failing to produce code that adhere to the principles

in the example -2- there is nothing explicit about the principles (this is were i mis?-use the word “automatic”) still the practices prescribed by tdd with mocks lead to remove and prevent many violations of the principles.
in my experience have observed 1 team that so produced code more adherent to the principles without an explicit policy to do so. then team observed the characteristics of the code (more easy to understand and change) and some member got interested into the principles, studied them and began to apply them in a more aware, intentional and extensive way.

if i understood your point, you suggest to apply tdd and also as in -1- teach design principles and ask the team to follow them.

while my point is to apply tdd with mock objects and support the observations of the effects on the code produced and support any curiosity about the principles from team members

is this correct? in your experience have you observed dynamic similar to the examples -1- and -2- or totally different ones?

if you arrived here, thank you for reading all this long comment.

when you say “the ability of the team members to learn from this and adapt” surely we cannot think this as something “almost automatic”, can we? :-) And when you say “when the team do it right and learn from it” again, how do we know that we’re doing it right? How can we know how “right” is?

Instead if I understand correctly, I disagree when you say
> There is nothing “almost automatic” in this process.

XP is explicitly defined [1] to create a set of generative rules [2] that do have some automatic effects that works in combination with the ability of team members to learn from this and adapt coding to it [3].

Indeed when I read about CAS in [3] I recognized many concepts referenced in XP Explained and Cockburn make it clear too in [1].

What I can add is that TDD with mock objects can be very effective to guide the team toward the correct understanding and application of the design principles, when the team do it right and learn from it.

[1] Agile software development: the business of innovation, Highsmith-Cockburn, 2001, http://alistair.cockburn.us/Agile+software+development:+the+business+of+innovation

[2] Generative Systems, http://en.wikipedia.org/wiki/Generative_systems

[3] Complex adaptive systems (CAS), http://en.wikipedia.org/wiki/Complex_adaptive_system