Machiavellians are temperamentally predisposed to scheme and cheat (as explained here). However, they can’t have their way without trusting or foolish victims who ignore the warning signs.

Every con artist needs a rube capable of being gulled.

I’ve written many articles about what makes master manipulators tick, but what about people who fall victim to Machiavellian schemes because they are too trusting, too eager, too greedy, or too clueless? Even smart people can behave stupidly sometimes, but is there a profile for the type of person who is easily conned?

Not exactly.

However, there are some traits and characteristics that might place a person at higher risk for being rooked:

1. Being Impervious to "Trust"/"Don’t Trust" Cues

I once knew a home builder who gave the key to a brand-new home to a “buyer” in exchange for a post-dated earnest money check, simply because the man promised to pay cash and close in a week. The check bounced. Meanwhile, the con man had moved into the home and changed the locks. This was a case of being overly eager for a sale, perhaps being too greedy for easy money, and allowing these enticements to overshadow the obvious risk of granting access to a home prior to closing.

In one study, researchers had students attempt to cut in line to use a copy machine. When a student asked to cut in line without offering any excuse for the request, the answer was usually (but not always) no. When the student asked to cut in line, “because I’m about to miss a deadline and really need to make some copies,” the request was usually granted. And so a plausible explanation, whether or not it is true, is frequently successful in overcoming resistance. But that’s not the end of the story. If a student asked to cut in line just “because I need to make some copies,” the request was again granted more often than not. The mere pretense of offering an explanation for the request was successful at overcoming resistance most of the time.

I can’t tell you the number of times I’ve been caught off guard in a parking lot or at a gas station by someone claiming to be an out-of-towner whose car has run out of gas. (The “car” is always somewhere else and the beggar is on foot.) The first couple of times I heard this, I handed over some money while simultaneously thinking that this could be a scam; but what if they really need help? Now when I hear this, I break out laughing before the stranger gets halfway through his or her spiel. My response: “You guys really need to get some new material. That story was sad the first time I heard it, and it’s been funny ever since.”

2. The Dilution Effect

Let’s go back to the home builder who handed over the key. Here’s what the con artist told him:  I’m a lawyer moving here from out of state. I’m starting work at a local law firm in two weeks, so I need to move right away. I like this house, and it’s in my price range, so if we can come to an agreement, I’ll be able to pay cash and close within one week.

In hindsight, we know that these were lies to sucker the home builder. But assume you were the seller faced with a seemingly legitimate buyer under deadline to relocate and offering you a quick, cash sale. It's a plausible scenario and you have no reason to disbelieve it, but at the same time, you have no reason to abandon normal caution. Is there anything in the stranger's explanation that would justify giving him a key to the home prior to closing?

Of course there isn’t. The con artist just wants the key, and will probably offer some pretext, such as: “I’d like to have a decorator come in and measure for drapes.” Fine.  You (the seller) can meet the decorator, unlock the house, and stay until the decorator leaves. Or you can point out that the sale will close in one week and the decorator can come in at that time. The alternative is to be overly trusting, overly accommodating, and overly anxious for a sale.

The dilution effect is a psychological theory that states that trivial and irrelevant details tend to drown out or dilute relevant information when we are bombarded with both.  The scammer’s backstory of moving from out of state, starting work at a law firm, needing a house in a hurry, and so on, are extraneous details that drown out relevant questions such as, “How do I know any of this is true?” Or “What makes him expect that I would give him a key prior to closing?” Or “Why can’t this wait even one week?” Or “What’s the worst that could happen if I agree?”

3. Medical, Social, and Cultural Factors

People with lower intelligence, with mental impairments, as well as senior citizens suffering from dementia or other age-related deficiencies are, of course, more susceptible to being conned through no fault of their own. Environmental influences arising from the prevailing culture, or from one’s social activities or peer group, can also raise the risk of Machiavellian manipulation. An example is affinity fraud.

Many church groups have been plagued by members who become hucksters for some multi-level marketing scheme and who then plague other church members to join up or buy products at inflated prices. One of the largest affinity fraud schemes was perpetrated by the Baptist Foundation of Arizona, which collapsed after luring many of its faithful to invest money in bogus fixed-rate investments. More than 90,000 people were swindled, and their losses eventually reached $2.2 billion. Top executives of the foundation were sent to prison and ordered to pay restitution.

The single best clue that we are being set up for a con—other than a flashing neon sign that says “This guy is a crook”—is that sixth sense that someone is intruding into our boundaries. Asking for a key to a house one hasn’t bought yet is a breach of the seller’s personal boundaries. Dangling too-good-to-be-true bait in front of you to get you to abandon your normal caution and due diligence in financial dealings is a breach of your personal boundaries. Avoid allowing your own desire and trusting nature to be used against you by Machiavellian manipulators.

https://www.psychologytoday.com/blog/machiavellians-gulling-the-rubes/201608/are-you-easily-conned