How does identity impact segregation?

‘Identity politics is back’, opines a comment to my blog post The Trump Swerve. I admit to having difficulties with the concept of ‘identity’. To put my queasiness into perspective, let me take a roundabout way and reflect on ‘segregation’ instead.

The article, This Simple Experiment Shows How Easy It Is for Society to Become Segregated, which I shall discuss presently, allows me to examine the issue in a somewhat structured way.

What is segregation?

The two authors of the article do not define segregation: ‘But that’s not how society works. In reality, segregation is widespread: in residential neighbourhoods, at the workplace, in schools, even online.’

If one posits segregation, one should indicate what ‘non-segregation’ looks like. The text is unclear on this point. From the experiment the two authors engage in, one might infer that for them, segregation is any non-Brownian (or random) array of people scattered across a homogenous space.

From the asserted wide presence of segregation, the authors draw the policy conclusion: ‘Segregation is not a good thing: people who are physically separated are unlikely to exchange ideas, share resources, or resolve problems. Segregation worsens inequality and conflict.’

The article introduces the map below so as to prove its premise that segregation is rampant.

Segregation in New York is not a matter of law. We are talking here about de facto segregation. What might be its origins?

Segregation as optical or definitional artifice

Aggregation rules and coarse grain may help explain what appears on the map as segregation. If most resident couples were mixed, for example, would this show up on the map or would the aggregation rules and color dominance overwhelm the actual distribution? This is just a question.

A further point is definitional. The map highlights four ‘races’ and disallows crossbreeds. Assigning people of mixed parentage to either race is far from objective. Even self-declaration (e.g. in New Zealand) is a dubious criterion when it comes to affirmative action. On this basis, segregation might appear stronger than in reality. (Traditionally, in the USA, one ‘drop’ of black blood classified a person as ‘black’, unless they could pass as white. As long as slavery existed, ‘blackness’ was coded to the slave owner’s property: race was defined to maximise it. Although slavery was abolished, the census and birth certificates failed to recognise the new reality.)

The map highlights place of residence, i.e. where people sleep. Is this the relevant criterion nowadays? How would a map based on ‘place of work’ or ‘place of social interaction’ look? In the past, the railway tracks separated two social worlds, and one race alone moved, just to work. Is this still the case? If it is good to ‘exchange ideas, share resources, or resolve problems’, does it have to be all the time and by residence rather than by presence?

Agglomerations as fractal constructs

Agglomerations follow fractal rules (see Fractal Cities: A Geometry of Form and Function by Michael Batty). Fractal patterns repeat themselves over different length scales: if you zoom in on one small portion of a fractal, you will find a motif nearly identical to the pattern as a whole. Over time, the fractal network of streets may change from being multifractal, scaling spatially according to multiple rules, to monofractal, with a single scaling rule (e.g. London).

The fractal character of agglomerations is very old and has underlain ancient African cities (see African Fractals: Modern Computing and Indigenous Design by Ron Eglash). It may shape all sorts of settlement patterns, which change over time, yet leave a historical trace.

For our purposes, the insight suggests that what appears to be segregation may, at least in part, reflect both old and new settlement patterns that have little to do with de facto segregation.

A ‘simple’ experiment?

To explain the perceived pattern of segregation, the authors claim the following:

To explain why segregation might occur in otherwise tolerant societies, the Nobel Prize-winning economist Thomas Schelling proposed a model. Schelling imagined a world where two types of individuals (we’ll make them blue and yellow) are randomly located on a flat square world. In Schelling’s model, individuals prefer to have some similar neighbours, but they do not discriminate against different neighbours – in short, they are tolerant. If individuals are unhappy with their neighbourhood, they can freely move to a neighbourhood with a more preferable composition.

In the example below, the yellow individual is unhappy about her assigned location because she does not have enough yellow neighbours, so she decides to move to a new neighbourhood. But when she moves, the composition of both her old and new neighbourhoods change. As a result, an old yellow neighbour and a new blue neighbour also decide to move.

This causes a domino effect that leads neighbourhoods to separate into yellow and blue ghettos. In the end, although no single individual prefers it, everyone ends up in segregated neighbourhoods.

The first assumption – that people are located randomly on a flat square world – is questionable. The second assumption is even more problematic: that people are either yellow or blue, implying they possess a single and invariant identity.

There is no basis for this assumption; it is a requirement of the mathematical instrument used. People have many identities, which they continuously fore- or background depending on the situation (see Identity and Violence: The Illusion of Destiny by Amartya Sen). It is this ability to switch that gives the illusion of only having one, and this is a form of availability bias.

The article’s authors ‘improve’ on the Schelling model by going beyond tolerance – which to them is akin to indifference – and explicitly aiming for diversity. Unsurprisingly, the authors get what they want: integration. They conclude: ‘Segregation is not unavoidable, but there is a need to continue educating people about the benefits of diversity and to continue devising policies and incentives that prevent or ease segregation.’

When assumptions are questionable

Strip away the sociological context, and the ‘simple experiment’ proves what popular wisdom knew all along: ‘Birds of a feather flock together’. It looks as if the models just explain murmuration (which employs similar rules).

I would shy away, however, from suggesting any policy based on such simple models.

This post was first published on DeepDip.