3.6: All these strategies seem to imply that with development, some things are changing and some are staying the same. Is that right?

Exactly right, and this is where our relational systems meta-theory can give us eyes to see what is changing and what is staying the same. In the first strategy, in which we follow the same behavior across its lifespan, the part, that is the behavior (e.g., biting), is staying the same, but the role in plays in the whole (i.e., aggression) is changing, for example, first is plays a less important part, then it is replaced by other actions, then it may disappear, and its utilization at older ages reveals that it is part of a different whole (maybe psychopathology). The second strategy, in which we trace the changing proximal processes that lead to certain kinds of appraisals, it is the whole that we are holding constant, that is the appraisals, and the parts (i.e., the proximal processes that give rise to the appraisals) that are rapidly changing, even as the whole (i.e., the appraisals) continue to enable and constrain the parts (i.e., the subsequent proximal processes).

In the third strategy, in which organizational constructs guide our search across different developmental terrain, it is the concept, that is the function, that remains the same (e.g., proximity-seeking or communication) and everything else can be changing—the actions, the means, their structure or interrelations, the appraisals that guide them. These discussions start sounding very systems-y in that we start theorizing about the differentiation of new means to serve old functions, the integration of old means to serve functions in new ways, the substitution of new means, the emergence of new structures to serve functions, new uses for old means, and so on.

Whatever the strategy, the take home message is that the “problem” of developmental equivalence can be turned into an asset when researchers use it as a signpost, telling them that – here is some qualitative development—and urging them not to turn back. The recognition that developmental researchers are all interested in these pesky multilevel systems, that include lower-level actions that serve immediate goals, proximal processes in which they are embedded, appraisals to which these interactions give rise which in turn guide subsequent proximal processes, and the structures of these episodes are all bound up in the larger functions of the system. Lines of sight.

If we can keep our finger on one of these levels (the actions, the appraisals, or the functions) to hold it “constant,” we can cope with the frenetic movement at the other levels. For example, if we hold appraisals still, then they become like the duck sailing along smoothly on the surface of the water (seemingly continuous and so available to be captured with “equivalent” measures) whereas the proximal processes are busily churning up action below the surface, guided by the appraisals, but also feeding into them. If we pursue this metaphor long enough, we have to give our duck swimming lessons in that the means used to propel the appraisals change radically over time; maybe we will give our duck swim fins and then oars and then a small outboard motor. Anyway, we will need qualitatively different measures to capture them.

As you know by now, relational researchers realize that none of the parts of this complex and dynamic system are actually constant. Nevertheless, our finger holding a part still, temporarily creates a line of sight that we can use to capture one interesting view of our developing phenomena. And then we can move our finger to create another view and another. We will begin to see how the dynamic parts are creating some of the stability, for example, how children can experience the love and affection of their parents as constants only if the parents continually change the way that they interact with their child as he or she develops. Or how, for children to experience themselves as competent, they must have a series of systematically changing experiences in which they succeed, then they must succeed without help, then they must succeed at hard task without help, and then succeed at hard tasks without help when other’s don’t, and then succeed at hard tasks without help when other’s don’t using little effort.

What would mechanistic and organismic researchers say about developmental measurement equivalence?

Mechanistic	What problem? A behavior is a behavior is a behavior. Come on down from “aggression” and look at the specific behaviors, like “hitting” or “verbal theats.” We should be looking at their antecedents and consequences, the contingencies that shape and reinforce them, the discriminative stimuli that elicit them, and how they generalize across situations. If you want, you can compare how these antecedents and consequences differ or change across different ages.
Organismic	What problem? We are interested in qualitative changes—they are not only the rule, they are the point. Development is inherently “nonequivalent,” so we should be looking for transformation, reorganization, or restructuring. We want to see how something turns into something else—for example, how aggression is transformed from physical to verbal, or transformed to words and negotiation.
Example	Development of emotion regulation (Kopp, 1989, Table 2)

	Phases	Approx. ages	Features	Cognitive requisites
	Neurophysiol-ogical modulation	Birth to 2-3 mo.	Modulation of arousal, activation of organized patterns of behavior
	Sensorimotor modulation	3-9 m. +	Changing behavior is response to events and stimuli in the environment
	Control	12-18 m. +	Awareness of social demands of a situation & initiate, maintain, & cease physical acts, communication, etc. accordingly; compliance, self-initiated monitoring	Intentionality, goal directed behavior, conscious awareness of action, memory of existential self
	Self-control	24 m. +	As above; delay upon request; behave according to social expectations in the absence of external monitors	Representational thinking and recall memory, symbolic thinking, continuing sense of identity
	Self-regulation	36 m. +	As above, flexibility of control processes that meet changing situation demands	Strategy production, conscious introspection, etc.