Key Idea #1: The Persuasion in Parallel pattern is common

Here's a schematic instance of the PiP pattern.

Suppose on average, red triangles oppose a policy, blue circles support it.

When exposed to persuasive information, both groups update their views "in parallel"

Here's a good example from a reanalysis and MTurk replication of Chong and Druckman (2010)

treatment: persuasive info for or against the patriot act
outcome: support for the patriot act
covariate: partisanship

The groups update their support for the Patriot Act in parallel.

My claim is: the PiP pattern is common, as long as

- The treatment is persuasive information

- The outcome is policy support

- the covariate is pre-treatment (I've looked at baseline support, pid, ideology, education, race, age, gender)

The evidence for the claim comes from a meta-analysis 23 persuasion experiments. Some are original experiments, some are replication studies, and some are reanalyses.

Here's all the evidence in the book:

We can look at the PiP pattern in another way by correlating the CATEs, split by many different covariates.

These are the figures that convince me of key idea #1

The book discusses many design objections like:

- What does parallel even mean?
- Do we have the right covariate?
- What about measurement error?

If you've clicked through this far -- thank you!

I hope you're at least provisionally on board with the idea that the Persuasion in Parallel pattern is common.

On to key idea #2!

Key idea #2:

Here is a typology of political communication treatments and outcomes:

- two kinds of treatments: persuasive information and group cues

- two kinds of outcomes: policy attitudes and affective evaluations

- People update their policy views "in parallel", but if the information is "counterattitudinal," people *dislike* the message and the messenger

- Group cues (information about which groups in society support which policies) have effects on attitudes that depend on group attachments

The upshot is that persuasion comes at an affective cost.

People *do not like* being persuaded, even though they update their views in the direction of info.

In other words, those being persuaded will complain about it!

Key Idea #3: Motivated reasoning theory has a problem

MR says we have accuracy goals and directional goals when processing info.

If directional goals dominate, then the effects of info should have opposite signs for groups with opposing directions.

But since the PiP pattern is common, either...

1. Accuracy goals dominate when people encounter persuasive information or

2. Motivated reasoning isn't a good model of information processing (or at least, the MR-predicted backlash doesn't seem to occur)

Thank you again for reading this far!

Those were the three key ideas:

1. PiP pattern is common
2. A typology of political communication treatments and outcomes
3. Motivated reasoning theory has a problem