Corrosive actions are behaviours that derail conversation in real time. They are not defined by intention, motivation, or emotional history, but by what they do to the interaction as it unfolds. When they appear, conversation stops being shared, regulation breaks down, and forward movement becomes difficult or impossible. Over time, repeated use of these behaviours corrodes the relationship itself.

At a structural level, corrosive actions can be grouped into two broad categories based on how they modulate relational intensity. One category increases intensity by engaging the other person. The other reduces intensity by disengaging from the interaction. Both interrupt conversation. Both destabilise regulation. The distinction is not about good or bad strategies, but about their observable effect on the exchange.

The first category involves actions that engage the other person and drive intensity upward. These behaviours apply pressure to the interaction. They seize the conversational space, provoke activation, and collapse reciprocity. As intensity escalates, the original thread of the conversation is lost. What began as an exchange becomes a defensive interaction organised around managing threat rather than maintaining contact. Repair becomes unavailable because the conversation can no longer hold it.

The second category involves actions that reduce relational intensity by disengaging from the interaction. This is often described as avoidance, shutting down, or minimising. It shows up when someone steps back from the conversation, goes quiet, changes the topic, or makes themselves unavailable as a participant. These actions stop the interaction rather than resolving it.

The effect is consistent. The conversation cannot continue because one person is no longer participating in it. Reciprocity breaks down and the interaction fragments. While surface intensity may drop briefly, regulation is not restored. Very often, the lack of response increases activation and leads to escalation rather than resolution.

Although these two categories look very different, their impact on conversation is the same. One overwhelms the interaction; the other withdraws from it. Both disrupt shared regulation and prevent forward movement. Over time, these actions become linked. One person’s corrosive action triggers the other’s, and the interaction becomes organised around managing each other’s responses rather than maintaining conversation.

This is why the focus is not on explaining these behaviours, but on interrupting them. Corrosive actions distort the very conversation through which repair is meant to happen. When conversation is repeatedly derailed, fragmented, or shut down, repair becomes structurally impossible. For many couples, nothing changes not because insight is lacking, but because the medium of change itself — conversation — has been consistently undermined.